California courts seem to be developing a consensus that rejects the widely-accepted unmasking test known as the Dendrite standard, which was established in a 2001 New Jersey appellate decision, Dendrite International v. Doe.
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But in order to do this, the problem of dendrite formation must be addressed.
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Doe that the other prongs of the Dendrite test adequately protect posters' First Amendment rights.
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Why it matters: These dendrite spikes are holding back potentially massive advances in drawing more energy from a lithium-ion battery.
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Some look like the traditional six-armed crystal you drew back in nursery school, which is technically known as a dendrite.
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This image is a reconstruction of a dendrite (red) and its axons (multicolored) in the outer part of a mouse's brain.
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Through a chemical and electrical transmission, the single-stemmed axon of one neuron talks to the branched root-like dendrite of another.
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The multistep Dendrite test calls for courts, in the final step of their analysis, to balance the First Amendment rights of anonymous posters against the necessity of exposing their identities.
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The dendrite has little knobby spines that stick out and receive chemical messages passed from another neuron's axon across the synapse, or gap between them, via the tiny white sacs called vesicles.
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In order to get a better handle on what is actually going on inside the battery during charging and recharging, the Michigan team created a see-through battery which allows them to use a high resolution microscope to watch dendrite formation in real time.
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Parker began experimenting with translating the drawings to clay, and the resulting dendrite-shaped sconces, blood-red side tables and lamps with branchlike protrusions topped with the vintage shades that Parker finds at antique shops and church garage sales were recently on view at the Brooklyn design showroom Love House.
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The apical dendrite rises from the apex of the pyramidal cell's soma. The apical dendrite is a single, long, thick dendrite that branches several times as distance from the soma increases and extends towards the cortical surface.
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An oblique dendrite is a dendrite that branches from an apical dendrite that emerges from the apex of a pyramidal cell. Oblique dendrites typically branch one to two times before terminating. Dendrites are extensions of the cell body of a neuron.
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Also, dendrite thickness of a whole dendrite cannot be measured, only the mean thickness of the dendrites within a shell. Dendrite length of a given dendrite also cannot be determined, since dendrites do not necessarily emanate radially from the soma; dendrites can curve, cross the same circles multiple times, or extend tangentially and not cross at a circle at all. Additionally, Sholl analysis can be time consuming, and automated analysis software is limited.
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Dendrite International, Inc. v. Doe No. 3, 342 N.J. Super. 134, 775 A.2d 756 (App. Div. 2001), is a New Jersey Superior Court case in which Dendrite International, Inc.
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Sustained attention and apical dendrite activity in recurrent circuits. Brain Research Reviews, 50, 86-99. LaBerge, D. (2006). Apical dendrite activity in cognition and consciousness. Consciousness and Cognition, 15, 235-257.
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At the majority of synapses, signals cross from the axon of one neuron to a dendrite of another. However, synapses can connect an axon to another axon or a dendrite to another dendrite. The signaling process is partly electrical and partly chemical. Neurons are electrically excitable, due to maintenance of voltage gradients across their membranes.
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Dendritic spines are absent on the soma, while the number increases away from it. The typical apical dendrite in a rat has at least 3,000 dendritic spines. The average human apical dendrite is approximately twice the length of a rat's, so the number of dendritic spines present on a human apical dendrite could be as high as 6,000.
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In Drosophila, flamingo mutants were found to have abnormal dendrite branching, outgrowth and routing. Kimura et al. proposed that flamingo regulates dendrite branch elongation and prevents the dendritic trees of adjacent Drosophila sensory neurons from having overlap of dendritic arbors. A study of mammalian flamingo homolog CELSR2 found that it is involved in the regulation of dendrite growth.
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Environmental enrichment affects the complexity and length of the dendrite arbors (upon which synapses form). Higher-order dendrite branch complexity is increased in enriched environments, as can the length, in young animals, of distal branches.
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Homophilic Dscam interactions control complex dendrite morphogenesis. Neuron. 54:417–27Matthews BJ, KimME, Flanagan JJ, Hattori D, Clemens JC, et al. 2007. Dendrite self-avoidance is controlled by Dscam. Cell 129:593–604Schreiner D, Weiner JA. 2010.
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The term "dendrite" comes from the Greek word dendron (δενδρον), which means "tree".
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A defining characteristic of Purkinje cells in the cerebellum is the apical dendrite.
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In Chrysoperla carnea, the green lacewing, the organ is involved in sexual behaviour and interindividual or even interspecies communication. A velum spans the interior of each leg and is formed by cap cells. Three scolopidia stretch from the velum to the leg wall, each containing one sensory neuron with a dendrite and attached cilia. The dendrite is accompaigned by a so-called scolopale cell which generates an electron-rich intracellular structure surrounding the dendrite.
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An apical dendrite is a dendrite that emerges from the apex of a pyramidal cell. Apical dendrites are one of two primary categories of dendrites, and they distinguish the pyramidal cells from spiny stellate cells in the cortices. Pyramidal cells are found in the prefrontal cortex, the hippocampus, the entorhinal cortex, the olfactory cortex, and other areas. Dendrite arbors formed by apical dendrites are the means by which synaptic inputs into a cell are integrated.
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The Contagious Apparitions of Dambarey Dendrite is a 2013 Nepali drama short film, directed by Pooja Gurung, Bibhusan Basnet in their debut. The film stars Anupam Sharma in the lead role. The Contagious Apparitions of Dambarey Dendrite is about hallucinating Dambarey (Anupam Sharma) and his street gang.
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The trial judge felt that Dendrite had failed to prove that it was harmed by the allegations, and found that the conduct of Does No. 3 and 4 did not warrant the revocation of their constitutional protections. Dendrite appealed the decision with respect to Doe No. 3.
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A 2018 study identified nanoporous ceramic separators that block Li dendrite growth up to critical current densities.
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Striatal axons may in fact simply cross the dendrite and give a single synapse. More frequently the striatal axon curves its course and follow the dendrite forming "parallel contacts" for a rather short distance. The average length of parallel contacts was found to be 55 micrometres with 3 to 10 boutons (synapses). In another type of axonal pattern the afferent axon bifurcates and gives two or more branches, parallel to the dendrite, thus increasing the number of synapses given by one striatal axon.
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The CoDi model does not use explicit synapses, because dendrite cells that are in contact with an axonal trail (i.e. have an axon cell as neighbor) collect the neural signals directly from the axonal trail. This results from the behavior of axon cells, which distribute to every neighbor, and from the behavior of the dendrite cells, which collect from any neighbor. The strength of a neuron-neuron connection (a synapse) is represented by the number of their neighboring axon and dendrite cells.
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Ideally, the lithium deposition occurs evenly on the anode. However, if the growth is uneven, dendrites form. Stable solid electrolyte interphase (SEI) was found to be the most effective strategy for inhibiting dendrite growth and increasing cycling performance. solid-state electrolytes (SSEs) may prevent dendrite growth, although this remains speculative.
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This is a neuromuscular junction. There is a presynaptic unit (axon), a synapse and a postsynaptic unit (dendrite). Neurotransmitters are released into the synapse. The neuromuscular junction in the CNS can be composed of a presynaptic unit located at an axon terminal with synaptic vesicles and a postsynaptic unit located at a dendrite.
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Development of an apical dendrite theory of cognition, attention, and consciousness. A series of papers explored the hypothesis that the apical dendrite is not "just another dendrite" but has its own special functions (2001, 2002, 2005, 2006, 2007). The hypothesis that the apical dendrite resonates was illustrated informally by LaBerge and his daughter, Anne La Berge in three performances of a work entitled Resonant Dendrites, (2006, 2007, 2009), which featured film, narrative voice samples and music. A formal description of a theory of electric resonance in apical dendrites appeared in an article by Kasevich & LaBerge (2010), which shows how an apical dendrite can fine tune its own membrane oscillations to a specific peak frequency, and narrow the width of the resonance curve around this peak to less than 1 Hz. This refinement enables its associated cortical circuit to generate a specific resonant ("carrier") frequency by which the circuit can separate its signaling from that of other circuits.
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Distances between successive branch points are shorter for basal dendrites. The basal dendrite however has approximately 3 fold fewer endings per primary dendrite. This and the lower maximum branch order suggest lower complexity than apical dendritic trees. Basal dendrites have a shorter distance to the tips and a more restricted range than apical dendrites.
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Polymer electrolytes are promising for minimizing the dendrite formation of lithium. Polymers are supposed to prevent short circuits and maintain conductivity.
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A reconstruction of a pyramidal cell. Soma and dendrites are labeled in red, axon arbor in blue. (1) Soma, (2) Basal dendrite, (3) Apical dendrite, (4) Axon, (5) Collateral axon. One motivation for skipping over layers is to avoid the problem of vanishing gradients, by reusing activations from a previous layer until the adjacent layer learns its weights.
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The Linear Method is the analysis of the function N(r), where N is the number of crossings for a circle of radius r. This direct analysis of the neuron count allows the easy computation of the critical value, the dendrite maximum, and the Schoenen Ramification Index. Critical Value: The critical value is the radius r at which there is a maximum number of dendritic crossings, this value is closely related to the dendrite maximum. Dendrite Maximum: This value is the maximum of the function N(r), as specified by the Critical Value for a given data set.
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Journal of Neurobiology. 2001;49:245–253. Apical dendrites are studied in many ways. In cellular analysis, the electrical properties of the dendrite are studied using stimulus responses. A single surface shock of the cerebral cortex induces a 10–20 ms negative potential, a manifestation of the summed excitatory post-synaptic potentials (EPSPs) evoked in the distal portions of the apical dendrite.
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These spines increase the number of axons from which the dendrite can receive information. Dendritic spines are very plastic, meaning they can be formed and eliminated very quickly, in the order of a few hours. More spines grow on a dendrite when it is repetitively activated. Dendritic spine changes have been correlated with long-term potentiation (LTP) and long-term depression (LTD).
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Zipcode binding protein 1 (ZBP1) was shown to regulate dendritogenesis (dendrite formation) in hippocampal neurons. This protein is different from the nucleic acid sensor ZBP1.
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Major elements in synaptic transmission. An electrochemical wave called an action potential travels along the axon of a neuron. When the wave reaches a synapse, it provokes release of a small amount of neurotransmitter molecules, which bind to chemical receptor molecules in the membrane of the target cell. Most neurons send signals via their axons, although some types are capable of dendrite-to-dendrite communication.
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Passive cable theory describes how voltage changes at a particular location on a dendrite transmit this electrical signal through a system of converging dendrite segments of different diameters, lengths, and electrical properties. Based on passive cable theory one can track how changes in a neuron's dendritic morphology impacts the membrane voltage at the cell body, and thus how variation in dendrite architectures affects the overall output characteristics of the neuron. Electrochemical signals are propagated by action potentials that utilize intermembrane voltage-gated ion channels to transport sodium ions, calcium ions, and potassium ions. Each ion species has its own corresponding protein channel located in the lipid bilayer of the cell membrane.
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The M-cell has two primary aspiny (lacking dendritic spines) dendrites which receive segregated inputs from various parts of the neural system. One dendrite projects laterally and the other projects either in the ventral or medial direction, depending on the species. The ventral dendrite receives information from the optic tectum and spinal cord while the lateral dendrite receives inputs from the octovolateralis systems (the lateral line, acoustic inputs from the inner ear, and inertial information from the statoliths brought by the cranial nerve VIII). The fibers from the ipsilateral cranial nerve VIII terminate in excitatory mixed electrical and glutamatergic synapses on the M-cell.
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Evidence suggests that dendrite arborization and synapse maturation 1 (Dasm1), an Ig superfamily member, is involved in the maturation of synapses, essentially "awakening" the silent synapses.
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Does, was a lawsuit brought by Dendrite International, Inc. (since acquired by Cegedim),Business Wire. Dendrite's Shareholders Approve Acquisition by Cegedim. Retrieved on 2011-03-01.
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LaBerge, D. and Kasevich, R.S. (2007). The apical dendrite theory of consciousness, Neural Networks, 20,1004-1020. LaBerge, A. (2009). Resonant Dendrites: Music for flute and computer.
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The UBC has a round or oval cell body with usually a single short dendrite that ends in a brush-like tuft of short dendrioles (dendrites unique to UBCs). These brush dendrioles form very large synaptic junctions. The dendritic brush and the large endings of the axonal branches are involved in the formation of cerebellar glomeruli. The UBC has one short dendrite where the granule cell has four or five.
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Sunderland, MA: Sinauer Associates, Inc.; 2004 Each mitral cell extends a primary dendrite to a single glomerulus, where the dendrite gives rise to an elaborate tuft of branches onto which the primary olfactory axons synapse. Each glomerulus in the mouse model, for example, contains approximately 25 mitral cells which receive innervation from approximately 25,000 olfactory receptor axons. The convergence increases the sensitivity of mitral cells to odor detection.
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The brain has structures similar to residual nets, as cortical layer VI neurons get input from layer I, skipping intermediary layers. In the figure this compares to signals from the apical dendrite (3) skipping over layers, while the basal dendrite (2) collects signals from the previous and/or same layer.Some research indicates that there are additional structures here, so this explanation is somewhat simplified. Similar structures exists for other layers.
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Claire Trevor School of the Arts, University of California, Irvine. Kasevich, R.S., and LaBerge, D. (2010). Theory of electric resonance in the neocortical apical dendrite. PLoS ONE, 6(8): e23412.
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The crystal growth continues in three dimensions, the atoms attaching themselves in certain preferred directions, usually along the axes of a crystal, forming a characteristic tree-like structure of a dendrite.
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In this case, the court holds that only the first and third prongs of the Dendrite test are relevant, and thus adopts a summary judgement standard based on these two prongs.
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Scholl analysis estimates the amount and distributions of dendrite material by counting numbers of intersections of dendrites with an overlay of concentric rings centered at the soma. Medial prefrontal cortex layer II-III pyramidal neurons showed significant reorganization with a 21% increase in proximal apical dendrite arbors and a decrease of 58% in distal apical dendrite arbors. These results are in contrast to the changes in the hippocampal CA3 dendritic arbors, in which only regressive changes were observed. One possible explanation proposed in these studies is that the atrophy of distal dendrites in II-III layer pyramidal neurons results directly from the loss of input from changed CA3 pyramidal neurons, as both CA1 and CA3 project directly into the medial prefrontal cortex.
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Additionally, the presence of these channels provides a mechanism by which the neuron can suppress and regulate the backpropagation of action potentials through the dendrite (Vetter 2000). Pharmacological antagonists of these channels promoted the frequency of backpropagating action potentials which demonstrates their importance in keeping the cell from excessive firing (Waters et al., 2004). Results have indicated a linear increase in the density of A-type channels with increasing distance into the dendrite away from the soma.
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Action potentials may be first generated at the dendrite if stimulated by strong synchronous synaptic inputs.Golding NL, Spruston N. 1998. Dendritic sodium spikes are variable triggers of axonal action potentials in hippocampal CA1 pyramidal neurons. Neuron 21:1189-1200 The ability of a dendrite to initiate an action potential is not only highly dependent on synaptic input but also on the number of voltage-gated channels and density of voltage-gated channels present in the membrane.
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Amplitude and kinetics of the electrical signal vary as a function of position within the dendrite and signal frequency. The major trigger for CA3 discharge is the afferent input from the dentate gyrus granule cells, from which mossy fiber terminals create very complex synapses on the proximal part of the CA3 apical dendrite in the stratum lucidum. Here they contact very complex dendritic spines. Glutamate release from single terminals evokes a large non-NMDA mediated EPSP.
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In long term depression (LTD) the GluR subunits of AMPARs undergo endocytosis. Temporal differences in signaling over the course of neuron maturation suggest that the most promising studies of arbor development and synaptogenesis in the future are going to occur in intact brain systems. Another model studied in apical dendrite development is the rat. Injection of tetanus toxin into neonatal rats has shown that growth of apical dendrites occurs normally during signal deprivation while basal dendrite growth is restricted.
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Pyramidal cells in rats have been shown to undergo many rapid changes during early postnatal life. Between postnatal days 3 and 21, pyramidal cells have been shown to double in the size of the soma, increase in length of the apical dendrite by fivefold, and increase in basal dendrite length by thirteenfold. Other changes include the lowering of the membrane's resting potential, reduction of membrane resistance, and an increase in the peak values of action potentials.
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It is particularly important in most glutamatergic-mediated synapses as well as GABA-mediated synapses. It plays a role in dendrite formation by melanocytes and in secretory granule priming in insulin secretion.
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Elements of Molecular Neurobiology. 3rd ed. Chichester, West Sussex England: John Wiley & Sons Ltd; 2002. The apical dendrite of a large pyramidal neuron in the cerebral cortex may contain thousands of spines.
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All these molecules interplay with each other in controlling dendritic morphogenesis including the acquisition of type specific dendritic arborization, the regulation of dendrite size and the organization of dendrites emanating from different neurons.
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The spine apparatus occupies a large portion of the volume of the spine stalk, which may increase the longitudinal resistance between spine and dendrite Therefore, the spine apparatus could have a direct effect on the membrane potential of the spine plasma membrane when the synapse is active. The connection to the smooth endoplasmic reticulum suggests a potential pathway for the transfer of proteins and lipids between the spine and dendrite. The spine apparatus could also function as a reservoir for calcium ions.
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Another problem posed in the same year by Knaster, on the existence of an uncountable collection of dendroids with the property that no dendroid in the collection has a continuous surjection onto any other dendroid in the collection, was solved by and , who gave an example of such a family.. Previously announced in 2006.. A locally connected dendroid is called a dendrite. A cone over the Cantor set (called a Cantor fan) is an example of a dendroid that is not a dendrite.
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The main intrinsic granule cell in the vertebrate olfactory bulb lacks an axon (as does the accessory neuron). Each cell gives rise to short central dendrites and a single long apical dendrite that expands into the granule cell layer and enters the mitral cell body layer. The dendrite branches terminate within the outer plexiform layer among the dendrites in the olfactory tract. In the mammalian olfactory bulb, granule cells can process both synaptic input and output due to the presence of large spines.
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It has been determined from electrophysiological data that excitatory synapses on proximal apical dendrites of prefrontal cortex pyramidal neurons serve to amplify excitatory post-synaptic potential (EPSP) signals generated in distal apical dendrites. This suggests that reduction in distal dendrite mass due to the stress hormone elevation may result in an increase in proximal apical dendrite complexity as the proximal apical dendrites attempt to offset the reduced distal apical dendrite signals. Serotonergic alterations and alterations in glutamate release in the prefrontal cortex indicate that the neurochemical mechanisms altering structure in both the hippocampus and prefrontal cortex are similar. The division of management between extrinsic and intrinsic inputs to the dendrites in the piriform cortex (mentioned above) is also seen to a lesser degree in the medial prefrontal cortex.
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A dendritic spine (or spine) is a small membranous protrusion from a neuron's dendrite that typically receives input from a single axon at the synapse. Dendritic spines serve as a storage site for synaptic strength and help transmit electrical signals to the neuron's cell body. Most spines have a bulbous head (the spine head), and a thin neck that connects the head of the spine to the shaft of the dendrite. The dendrites of a single neuron can contain hundreds to thousands of spines.
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Animated GIF of dendrite formation – NASA The Isothermal Dendritic Growth Experiment (IDGE) is a materials science solidification experiment that researchers will use to investigate a particular type of solidification called dendritic growth. Dendritic solidification is one of the most common forms of solidifying metals and alloys. When materials crystallize or solidify under certain condition, they freeze unstably, resulting in tiny, tree-like crystalline forms called dendrites. Scientist are particularly interested in dendrite size, shape, and how the branches of the dendrites interact with each other.
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Generally, synaptic signals that are received by the dendrite are combined in the soma in order to generate an action potential that is then transmitted down the axon toward the next synaptic contact. Thus, the backpropagation of action potentials poses a threat to initiate an uncontrolled positive feedback loop between the soma and the dendrites. For example, as an action potential was triggered, its dendritic echo could enter the dendrite and potentially trigger a second action potential. If left unchecked, an endless cycle of action potentials triggered by their own echo would be created.
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Animated GIF of dendrite formation - NASA The Isothermal Dendritic Growth Experiment (IDGE) is a materials science solidification experiment that researchers use on Space Shuttle missions to investigate dendritic growth in an environment where the effect of gravity (convection in the liquid) can be excluded. Dendritic solidification is one of the most common forms of solidifying metals and alloys. When materials crystallize or solidify under certain conditions, they freeze unstably, resulting in dendritic forms. Scientists are particularly interested in dendrite size, shape, and how the branches of the dendrites interact with each other.
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Dynamic morphometrics and other imaging techniques have been used to observe both dendrite growth and synaptogenesis—two processes between which the relationship is not well understood. Non-spiny dendritic arbors expressing a fluorescent postsynaptic marker protein were imaged as they arborized (in the zebrafish larvae), and this confirmed the role of newly extended dendritic filopodia in synaptogenesis, their maturation into dendritic branches, and the result, namely, growth and branching of the dendritic arbor. These findings support the model wherein synapse formation can direct dendrite arborization, a basic tenet of the synaptotropic hypothesis.
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This growth direction may be due to anisotropy in the surface energy of the solid–liquid interface, or to the ease of attachment of atoms to the interface on different crystallographic planes, or both (for an example of the latter, see hopper crystal). In metallic systems, interface attachment kinetics is usually negligible (for non-negligible cases, see dendrite (crystal)). In metallic systems, the solid then attempts to minimize the area of those surfaces with the highest surface energy. The dendrite thus exhibits a sharper and sharper tip as it grows.
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When in the nanoscale, iron oxides will remain permanently magnetized at lengths greater than 50 nm and will become magnetized at lengths smaller than 50 nm. Since these platelets have been observed in collections of 5-10, they are thought to form dipoles local to the dendrite they are present in. These local magnetic changes then cause a mechanical response along the membrane of the nerve cell, leading to a change in ion concentrations. This ion concentration, with respect to the other dendrite clusters is believed to form the magnetic sense.
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Dendrites may be used to model certain types of Julia set.. For example, if 0 is pre-periodic, but not periodic, under the function f(z) = z^2 + c, then the Julia set of f is a dendrite..
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This indicates that neural activity is critical to new dendrite formation.Groc L PZ, Gustafsson B, et al. In vivo blockade of neural activity alters dendritic development of neonatal CA1 pyramidal cells. European Journal of Neuroscience. 2002;16:1931–1938.
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Branching dendrites of salt (sodium chloride) on the surface of a century egg. Dendritic crystallization after melting inside sealed ampules of rubidium and caesium metal. In chemistry, a dendrite is a crystal that branches into two parts during growth.
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Von Economo neurons, also known as spindle neurons, found in a few select parts of the cerebral cortex of apes and some other intelligent animals, possess a single axon and dendrite and as such have been described as bipolar.
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The so-called Dendrite standard was adopted by the Arizona Supreme Court in Mobilisa, Inc. v. Doe,170 P.3d 712 (pdf) (Ariz. 2007). Retrieved on 2009-03-15. and most recently, by Maryland's highest court in Independent Newspapers v. Brodie.
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Fractal curves and fractal patterns are widespread, in nature, found in such places as broccoli, snowflakes, feet of geckos, frost crystals, and lightning bolts. See also Romanesco broccoli, dendrite crystal, trees, fractals, Hofstadter's butterfly, Lichtenberg figure, and self-organized criticality.
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An adrenergic nerve fibre is a neuron for which the neurotransmitter is either adrenaline (epinephrine), noradrenaline or dopamine. These neurotransmitters are released at a location known as the synapse, which is a junction point between the axon of one nerve cell and the dendrite of another. The neurotransmitters are first released from the axon and then bind to the receptor site on the dendrite. Adrenergic nerve terminals are found in the secondary neurons of the sympathetic nervous system, one of two deviations of the autonomic nervous system which is responsible for the fight-or-flight response.
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Synapses can be classified by the type of cellular structures serving as the pre- and post-synaptic components. The vast majority of synapses in the mammalian nervous system are classical axo-dendritic synapses (axon synapsing upon a dendrite), however, a variety of other arrangements exist. These include but are not limited to axo-axonic, dendro- dendritic, axo-secretory, somato-dendritic, dendro-somatic, and somato-somatic synapses. The axon can synapse onto a dendrite, onto a cell body, or onto another axon or axon terminal, as well as into the bloodstream or diffusely into the adjacent nervous tissue.
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During development, dendrite morphology is shaped by intrinsic programs within the cell's genome and extrinsic factors such as signals from other cells. But in adult life, extrinsic signals become more influential and cause more significant changes in dendrite structure compared to intrinsic signals during development. In females, the dendritic structure can change as a result of physiological conditions induced by hormones during periods such as pregnancy, lactation, and following the estrous cycle. This is particularly visible in pyramidal cells of the CA1 region of the hippocampus, where the density of dendrites can vary up to 30%.
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Schoenen Ramification Index: This index is one measure of the branching of the neuronal cell being studied. It is calculated by dividing the Dendrite Maximum by the number of primary dendrites, that is, the number of dendrites originating at the cell's soma.
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The function group of the laboratory is led by Lily and largely focuses on the studies of ion channels, their assembly, and their dynamic response to neural activity. The development subgroup led by Yuh Nung has been engaged with questions surrounding dendrite morphogenesis.
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NASA animation of dendrite formation in microgravity. Manganese dendrites on a limestone bedding plane from Solnhofen, Germany. Scale in mm. Very commonly when the supersaturation (or degree of supercooling) is high, and sometimes even when it is not high, growth kinetics may be diffusion- controlled.
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Langerhans cells are named after Paul Langerhans, a German physician and anatomist, who discovered the cells at the age of 21 while he was a medical student. Because of their dendrite-like appearance, he mistakenly identified the cells as part of the nervous system.
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Further, neuronal activity also promotes the secretion of proBDNF from the dendrite which then effects pruning via binding to the p75NTR receptor. This work fascinatingly highlighted the distinct pathways and translational regulation of somatic versus dendritic BDNF. Orefice completed her graduate training in 2013.
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No uniform standard exists in the United States for determining the circumstances under which an anonymous online speaker may be unmasked.Miller, Jason. Who's Exposing John Doe Journal of Technology Law & Policy, Vol. 13, No. 1, 2008 The original Superior Court case, Dendrite International, Inc. v.
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The protein core can also function as a carrier for other therapeutic molecules, such as plasmid DNA. Dendrite polymer shells have a high volume to molecular weight ratio compared with traditional polymer shells. Using branched carbohydrates can give unique biological properties while maintaining molecular definition.
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Neurons from several brain regions, such as the neocortex, substantia nigra, and hippocampus have been found to contain autapses. Autapses have been observed to be relatively more abundant in GABAergic basket and dendrite-targeting cells of the cat visual cortex compared to spiny stellate, double bouquet, and pyramidal cells, suggesting that the degree of neuron self-innervation is cell-specific. Additionally, dendrite-targeting cell autapses were, on average, further from the soma compared to basket cell autapses. 80% of layer V pyramidal neurons in developing rat neocortices contained autaptic connections, which were located more so on basal dendrites and apical oblique dendrites rather than main apical dendrites.
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A basal dendrite is a dendrite that emerges from the base of a pyramidal cell that receives information from nearby neurons and passes it to the soma, or cell body. Due to their direct attachment to the cell body itself, basal dendrites are able to deliver strong depolarizing currents and therefore have a strong effect on action potential output in neurons. The physical characteristics of basal dendrites vary based on their location and species that they are found in. For example, the basal dendrites of humans are overall found to be the most intricate and spine-dense, as compared to other species such as Macaques.
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Alternatively, proprioceptive muscle spindles and other skin surface touch receptors such as Merkel cells, bulbous corpuscles, lamellar corpuscles, and hair follicle receptors (peritrichial endings) may involve the first neuron in this pathway. The sensory neurons in this pathway are pseudounipolar, meaning that they have a single process emanating from the cell body with two distinct branches: one peripheral branch that functions somewhat like a dendrite of a typical neuron by receiving input (although it should not be confused with a true dendrite), and one central branch that functions like a typical axon by carrying information to other neurons (again, both branches are actually part of one axon).
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In terms of anatomy, an auditory nerve fiber is either bipolar or unipolar, with its distal projection being called the peripheral process, and its central projection being called the axon; these two projections are also known as the "peripheral axon" and the "central axon", respectively. The peripheral process is sometimes referred to as a dendrite, although that term is somewhat inaccurate. Unlike the typical dendrite, the peripheral process generates and conducts action potentials, which then "jump" across the cell body (or soma) and continue to propagate along the central axon. In this respect, auditory nerve fibers are somewhat unusual in that action potentials pass through the soma.
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Manganese dendrites on a limestone bedding plane from Solnhofen, Germany. Scale in mm. A crystal dendrite is a crystal that develops with a typical multi-branching tree-like form. Dendritic crystal growth is very common and illustrated by snowflake formation and frost patterns on a window.
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An artificial neural network consists of a collection of simulated neurons. Each neuron is a node which is connected to other nodes via links that correspond to biological axon-synapse-dendrite connections. Each link has a weight, which determines the strength of one node's influence on another.
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The consistency of the liquid is altered: it becomes viscoelastic, which suppresses electroconvection and therefore prevents flow in patterns that enable dendrite formation. Archer also investigated the polymerization of a previously liquid electrolyte inside the electrochemical cell, which can improve the contact between the electrolyte and electrodes.
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The exact structure of the network and the position of the axon-dendrite neighbor pairs determine the time delay and strength (weight) of a neuron-neuron connection. This principle infers that a single neuron-neuron connection can consist of several synapse with different time delays with independent weights.
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Neuron and dendrite development are NMDA dependent. Rapidly growing dendrite arbors are more dynamic than slowly growing ones and dendrites themselves play an active role in their own development. It has been shown in studies that transport of HCN (hyperpolarization activated cyclic nucleotide) gated channel isoforms to dendritic fields of CA1 pyramidal neurons in the hippocampus occurs in an age- specific manner in the developing hippocampus.Bender RA BA, and Baram TZ. Neuronal Activity Influences the sub-cellular distribution of hyperpolarization-activated cation channels in hippocampal neurons. Epilepsia. 2005;46(supplement 8):92 Among the signals studied in this system is CaMKII a calcium/calmodulin-regulated serine/threonine kinase which is required for induction by not expression of long-term potentiation.
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23:147–156 In mouse retina the majority of ganglion cells are born at E17 (embryonic stage/day 17). At this age the retina has reached 25% of its mature sizeGrueber WB, Sagasti A, 2010. Self- Avoidance and Tiling: Mechanisms of Dendrite and Axon Spacing. Cold Spring Harbor Perspect. Biol.
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CaMKII mRNA is targeted to dendrites and both protein synthesis and enzyme activity are increased by strong synaptic input. Expression in Xenopus indicates that it is associated with the transition to slowed arbor growth. This suggests that activity promotes the reduction of dendrite branch growth and retraction, stabilizing the arbor configuration.
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David the Dendrite (c. 450–540), also known as David the tree-dweller and David of Thessalonika, is a patron saint of Thessaloniki. David became a monk at the Monastery of Saints Merkourios and Theodore outside Thessaloniki. Famed for his sound advice, he was hounded by crowds seeking words of wisdom and prayer.
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Fish glomerulus differs from the mammalian glomerulus in terms of the number of dendrites that it receives from the mitral cells. In a mammalian olfactory system, a single dendrite from a mitral cell enters a single glomerulus. However, in fish, one or more dendrites from mitral cells enter one or more glomerulus.
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Lithium anodes were used for the first lithium-ion batteries in the 1960s, based on the cell chemistry, but were eventually replaced due to dendrite formation which caused internal short-circuits and was a fire hazard. Replaced in commercial cell designs in the late-1970s by graphite carbon, effort continued in areas that required lithium, including charged cathodes such as manganese dioxide, vanadium pentoxide, or molybdenum oxide and some polymer electrolyte based cell designs. The interest in lithium metal anodes was re-established with the increased interest in high capacity lithium-air battery and lithium-sulfur battery systems. Research to inhibit dendrite formation has been an active area due in part to the need for a stable anode for these new beyond-lithium energy storage chemistries.
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Okamato, K. I., Nagai, T., Miyawaki, A., Hayashi, Y. (2004) Rapid and persistent modulation of actin dynamics regulates post-synaptic reorganization underlying bi-directional plasticity. Nature Neuroscience, 7:1104-1112. The increase in polymerized F-actin is due to the recruitment of G-actin monomers and the translation of actin mRNA in the dendrite.
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Both in humans and rodents, pyramidal cell bodies (somas) average around 20 μm in length. Pyramidal dendrites typically range in diameter from half a micrometer to several micrometers. The length of a single dendrite is usually several hundred micrometers. Due to branching, the total dendritic length of a pyramidal cell may reach several centimeters.
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Doron Aurbach and co- workers at Bar-Ilan University have extensively studied the role of solvent and salt in the formation of films on the lithium surface. Notable observations were the addition of LiNO3, dioxolane, and hexafluoroarsenate salts all appeared to create films that inhibit dendrite formation while incorporating reduced Li3As as a lithium-ion conductive component.
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There is strong evidence that after activation of CaMKII, CaMKII plays a role in the trafficking of AMPA receptors into the membrane and then the PSD of the dendrite. Movement of AMPA receptors increases postsynaptic response to presynaptic depolarization through strengthening the synapses. This produces LTP. Mechanistically, CaMKII phosphorylates AMPA receptors at the P2 serine 831 site.
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This increases the diffusion rate to the tip. In opposition to this is the action of the surface tension tending to flatten the protuberance and setting up a flux of solute atoms from the protuberance out to the sides. However, overall, the protuberance becomes amplified. This process occurs again and again until a dendrite is produced.
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In a growth phase a neural network is grown in the CA-space based on an underlying chromosome. There are four types of cells: neuron body, axon, dendrite and blank. The growth phase is followed by a signaling- or processing-phase. Signals are distributed from the neuron bodies via their axon tree and collected from connection dendrites.
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Action potentials initiated in the axon normally travel down the axon away from the soma. However, it is also possible for an action potential to travel in the opposite direction, invade the soma, and then travel down the dendrite as a dendritic spike.Ma J, Lowe G. 2004. Action potential backpropagation and multiglomerular signaling in the rat vomeronasal system.
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It has been observed from this and other models that there are rapid dendritic branch additions and retractions which lengthen the overall dendrite and accumulate more branches. This mirrors the development of axonal branches (both have a lifetime of approximately 10min). This activity decreases as neurons mature. Signals including glutamate from axon branches may increase branch additions.
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A neurite or neuronal process refers to any projection from the cell body of a neuron. This projection can be either an axon or a dendrite. The term is frequently used when speaking of immature or developing neurons, especially of cells in culture, because it can be difficult to tell axons from dendrites before differentiation is complete.
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Their protrusions, known as dendritic spines, are designed to capture the neurotransmitters released by the presynaptic neuron. They have a high concentration of ligand-gated ion channels. These spines have a thin neck connecting a bulbous protrusion to the dendrite. This ensures that changes occurring inside the spine are less likely to affect the neighboring spines.
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Although the grid was introduced long before any system of public transit would become necessary or available, its strict regularity provides sufficient flexibility for mapping transit routes. By contrast, derivatives of the Radburn-type network, particularly the non-cellular and strictly dendrite variety, are inflexible and force transit routes that are often long and circuitous resulting in an inefficient and costly service.
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A bipolar neuron, or bipolar cell, is a type of neuron that has two extensions (one axon and one dendrite). Many bipolar cells are specialized sensory neurons for the transmission of sense. As such, they are part of the sensory pathways for smell, sight, taste, hearing, touch, balance and proprioception. The other shape classifications of neurons include unipolar, pseudounipolar and multipolar.
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The influx of sodium ions causes an increase in voltage. If the voltage increases past a certain threshold, the sodium current activates other voltage-gated sodium channels transmitting a current along the dendrite. Dendritic spikes can be generated through both sodium and calcium voltage- gated channels. Dendritic spikes usually transmit signals at a much slower rate than axonal action potentials.
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Single crystal ingots of metal are produced in similar fashion to that used to produce high purity semiconductor ingots,Indium ingots , lesscommonmetals.com. i.e. by vacuum induction refining. Single crystal ingots of engineering metals are of interest due to their very high strength due to lack of grain boundaries. The method of production is via single crystal dendrite and not via simple casting.
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Dendritic spines are small with spine head volumes ranging 0.01 μm3 to 0.8 μm3. Spines with strong synaptic contacts typically have a large spine head, which connects to the dendrite via a membranous neck. The most notable classes of spine shape are "thin", "stubby", "mushroom", and "branched". Electron microscopy studies have shown that there is a continuum of shapes between these categories.
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In the development of certain filopodia into spines, filopodia recruit presynaptic contact to the dendrite, which encourages the production of spines to handle specialized postsynaptic contact with the presynaptic protrusions. Spines, however, require maturation after formation. Immature spines have impaired signaling capabilities, and typically lack "heads" (or have very small heads), only necks, while matured spines maintain both heads and necks.
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Data suggests that proximal apical and basal dendrites are more compressed but offer a wider local range of activity than distal apical dendrites. In CA3 neurons the inputs are stratified and run in bands parallel to the cell body layer. Dendritic attenuation of synaptic current is described by an exponential relationship. The closer to the body the dendrite, the higher the EPSP amplitude.
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Evf2 acts by forming a complex with Dlx4 that increases Dlx4 transcription activation ability and stability.Roberts T.C., Morris, K.V., and Wood, M.J.A. (2014), "The role of long non-coding RNAs in neurodevelopment, brain function and neurological disease." Philosophical Transactions of the Royal Society B. doi: 10.1098/rstb.2013.0507 Malat1, another neurological lncRNA, causes increased synaptic function and greater amounts of dendrite development.
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Directional solidification is the preferred technique for casting high temperature nickel-based superalloys that are used in turbine engines of aircraft. Some microstructural problems such as coarse dendritic structure, long dendrite side branches, and porosity hinder the full potential of single crystal ni-based alloys . This morphology can be understood by looking at the G/V ratio of a solidification where G is the temperature gradient in the melt ahead of the solidifying front and V is the rate of solidification. . This ratio must be maintained within a range to ensure single crystal formation with the correct microstructure of the coarse dendrite with side branches. . It has been found that increasing the solidification cooling rate further improves the mechanical properties and rupture life of single crystals grown by directional solidification due to refinement of the y’ precipitates .
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It is hypothesized in several studies that this could be accomplished by varying the overall frequency of synaptic activity in the distal apical dendrite. Since a constant barrage of synaptic activity would approximate a constant current injection, the overall level of synaptic activity in the distal apical dendrite could set the depolarization level of the entire neuron. When a more efficient proximal synaptic activity is superimposed upon a sub-threshold depolarization due to distal activity, the cell has a high probability of firing an AP. In CA3, it is the perforant path projection from the entorhinal cortical cells that provides synaptic input to the most distal dendrites of the pyramidal cells. Assuming a frequency average of 7 spikes/sec, as few as five randomly firing entorhinal cortical cells would cause a steady level of depolarization in the distal dendrites of CA3b pyramidal cells.
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Dendrites provide an enlarged surface area to receive signals from the terminal buttons of other axons, and the axon also commonly divides at its far end into many branches (telodendria) each of which ends in a nerve terminal, allowing a chemical signal to pass simultaneously to many target cells. Typically, when an electrochemical signal stimulates a neuron, it occurs at a dendrite and causes changes in the electrical potential across the neuron's plasma membrane. This change in the membrane potential will passively spread across the dendrite but becomes weaker with distance without an action potential. An action potential propagates the electrical activity along the membrane of the neuron's dendrites to the cell body and then afferently down the length of the axon to the axon terminal, where it triggers the release of neurotransmitters into the synaptic cleft.
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Lithium metal dendrite from the anode piercing through the separator and growing towards the cathode. Solid lithium (Li) metal anodes in solid-state batteries are replacement candidates in lithium-ion batteries for higher energy densities, safety, and faster recharging times. Such anodes tend to suffer from the formation and the growth of Li dendrites. Dendrites penetrate the separator between the anode and the cathode causing short circuits.
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A third approach produced rechargeable batteries that can be printed cheaply on commonly used industrial screen printers. The batteries used a zinc charge carrier with a solid polymer electrolyte that prevents dendrite formation and provides greater stability. The device survived 1,000 bending cycles without damage. A fourth group created a device that is one hundredth of an inch thick and doubles as a supercapacitor.
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The outer segment of the dendritic projection is attached to the inside surface of the cap. When the haltere is pushed to one side, the cuticle of the insect bends and the surface of the cap is distorted. The inner dendrite is able to detect this distortion and convert it to an electrical signal which is sent to the central nervous system to be interpreted.
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These gap junctions allow for virtually instantaneous transmission of electrical signals through direct passive flow of ions between neurons (transmission can be bidirectional). The main goal of electrical synapses is to synchronize electrical activity among populations of neurons. The first electrical synapse was discovered in a crayfish nervous system. :Chemical synaptic transmission is the transfer of neurotransmitters or neuropeptides from a presynaptic axon to a postsynaptic dendrite.
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Within the Xenopus tadpole model, several signaling systems have been studied. For example, in optical tectal neurons, dendrite arbor growth occurs approximately at the onset of retinal input. Many on the caudal tectate have “silent” synapses which are modulated only by N-methyl-D-aspartate (NMDA) receptors. As neurons mature, alpha-amino-3-hydroxy-5-methyl-4-isoxazole (AMPA) receptors are added, increasing synaptic transmission.
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At the farthest tip of the axon's branches are axon terminals, where the neuron can transmit a signal across the synapse to another cell. Neurons may lack dendrites or have no axon. The term neurite is used to describe either a dendrite or an axon, particularly when the cell is undifferentiated. Most neurons receive signals via the dendrites and soma and send out signals down the axon.
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The fastest recorded conduction speed of 210 m/s, is found in the ensheathed axons of some pelagic Penaeid shrimps and the usual range is between 90 and 200 m/s (cf 100–120 m/s for the fastest myelinated vertebrate axon.) In other cases as seen in rat studies an axon originates from a dendrite; such axons are said to have "dendritic origin". Some axons with dendritic origin similarly have a "proximal" initial segment that starts directly at the axon origin, while others have a "distal" initial segment, discernibly separated from the axon origin. In many species some of the neurons have axons that emanate from the dendrite and not from the cell body, and these are known as axon-carrying dendrites. In many cases, an axon originates at an axon hillock on the soma; such axons are said to have "somatic origin".
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While no solid-state batteries have reached the market, multiple groups are researching this alternative. The notion is that solid-state designs are safer because they prevent dendrites from causing short circuits. They also have the potential to substantially increase energy density because their solid nature prevents dendrite formation and allows the use of pure metallic lithium anodes. They may have other benefits such as lower temperature operation.
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A simple model for the neuron with predominantly potassium ions inside the cell and sodium ions outside establishes an electric potential on the membrane under equilibrium, i.e., no external activity, condition. This is called the resting membrane potential, which can be determined by Nernst Equation (Nernst, W. (1888)). An equivalent electrical circuit for a patch of membrane, for example an axon or dendrite, is shown in Figure 5.
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The neuron cell has three components – dendrites, soma, and axon as shown in Figure 1. Dendrites, which have the shape of a tree with branches, called arbor, receive the message from other neurons with which the neuron is connected via synapses. The action potential received by each dendrite from the synapse is called the postsynaptic potential. The cumulative sum of the postsynaptic potentials is fed to the soma.
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This disease is associated with neuronal death. However more general ageing considers loss of synaptic strength over neuronal death. When considering this situation the machinery for proper functioning of the brain is still present, but is in disarray. It has been shown that as much as a 46% decrease in dendrite spine number and density can occur in humans over 50 years old when compared to older participants.
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In the medical industry, 3D braided fabrics find applications in stent grafts, bifurcated stents, arm and leg prosthetics, and braided sutures. Surgeons initially used two separate implant procedures for bifurcation stenosis treatment, which was time-consuming. With the advent of 3D braided fabric, multiple dendrite circular braids were produced for bifurcation stenosis treatment, which is flexible and less time-consuming. With multiple tubular braided structures, various cardiovascular implants can be produced.
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Neuronal tiling is a phenomenon in which multiple arbors of neurons innervate the same surface or tissue in a nonredundant and tiled pattern that maximizes coverage of the surface while minimizing overlap between neighboring arbors.Grueber, W. B. & Sagasti, A. Self-avoidance and tiling: Mechanisms of dendrite and axon spacing. Cold Spring Harb. Perspect. Biol. 2, a001750 (2010) Hence, dendrites of the same neuron spread out by avoiding one another (self- avoidance).
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If the anisotropy is large enough, the dendrite may present a faceted morphology. The microstructural length scale is determined by the interplay or balance between the surface energy and the temperature gradient (which drives the heat/solute diffusion) in the liquid at the interface.J. A. Dantzig, M. Rappaz,Solidification, EPFL Press, 2009, pp. 287–298, As solidification proceeds, an increasing number of atoms lose their kinetic energy, making the process exothermic.
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Chen WR, Shen GY, Shepherd G, et al. 2002. Multiple modes of action potential initiation and propagation in mitral cell primary dendrite. Journal of Neurophysiology 88:2755-2764 For example, Mitral cells seem to serve both as projection neurons and as local interneurons. If the axonal output of mitral cell is shut down by somatic inhibition, local dendritic action potentials cause the mitral cell to release neurotransmitters into the environment.
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Stacked discs of the smooth endoplasmic reticulum (SERs) have been identified in dendritic spines. Formation of this "spine apparatus" depends on the protein synaptopodin and is believed to play an important role in calcium handling. "Smooth" vesicles have also been identified in spines, supporting the vesicular activity in dendritic spines. The presence of polyribosomes in spines also suggests protein translational activity in the spine itself, not just in the dendrite.
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However, synapses involving dendrites can also be axodendritic, involving an axon signaling to a dendrite, or dendrodendritic, involving signaling between dendrites. An autapse is a synapse in which the axon of one neuron transmits signals to its own dendrites. There are three main types of neurons; multipolar, bipolar, and unipolar. Multipolar neurons, such as the one shown in the image, are composed of one axon and many dendritic trees.
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All metal castings experience segregation to some extent, and a distinction is made between macrosegregation and microsegregation. Microsegregation refers to localized differences in composition between dendrite arms, and can be significantly reduced by a homogenizing heat treatment. This is possible because the distances involved (typically on the order of 10 to 100 µm) are sufficiently small for diffusion to be a significant mechanism. This is not the case in macrosegregation.
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Nedd9 expression may be important for recovery from stroke. Nedd9 is upregulated in the neurons of the cerebral cortex and hippocampus after transient global ischemia in rats. Induced Nedd9 is tyrosine phosphorylated, bound to FAK in dendrite and soma of neurons, and promotes neurite outgrowth, contributing into recovery of neurologic function after cerebral ischemia. Nedd9 has recently been implicated in the pathogenesis of autosomal dominant polycystic kidney disease (ADPKD).
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These cells synapse onto the dendrite of granule cells and unipolar brush cells. They receive excitatory input from mossy fibres, also synapsing on granule cells, and parallel fibers, which are long granule cell axons. Thereby this circuitry allows for feed-forward and feed-back inhibition of granule cells. The main synapse made by these cells is a synapse onto the mossy fibre - granule cell excitatory synapse in a glomerulus.
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The cells often have multiple primary dendrites innervating different glomeruli and they are sometimes called simply projection neurons, to indicate that they are the main neural element which project outside the olfactory bulb. The morphology of mitral cells was an advantage in early studies of synaptic processing, because the soma and the primary dendrite could be independently stimulated by appropriate positioning of stimulating electrodes in different layers of the olfactory bulb.
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Females have more dendrite chemical synapses within VMN while males have more somatic synapses within that region. In addition, the size of postsynaptic densities of axospinous and axosomatic synapses is sexually dimorphic, with males having larger density than females. Estrogen plays an important role in modulating the sexually dimorphic synaptic connectivity of VMN. Estradiol levels are high on proestrus rats and return to low levels on diestrus rats.
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For example, Al-Si-Cu-Mg alloys form Al5FeSi- plate like intermetallic phase, Chinese script like -Al8Fe2Si, Al2Cu, etc. The size and morphology of these intermetallic phases in these alloys control the mechanical properties of these alloys especially strength and ductility. The size of these phases depends on the secondary dendrite arm spacing, as well as the Si content of the alloy, of the primary phase in the micro structure.
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The court used Ramunno as an example of a motion to dismiss standard failing to screen "silly or trivial defamation suits." Thus, the court concluded, that in order to provide sufficient protection of anonymous internet speech and the First Amendment, a summary judgement standard is necessary. The court chose to base its summary judgement standard off of the precedent set by Dendrite International, Inc. v. Doe No. 3.
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The increase in the density of A-type channels results in a dampening of the backpropagating action potential as it travels into the dendrite. Essentially, inhibition occurs because the A-type channels facilitate the outflow of K+ ions in order to maintain the membrane potential below threshold levels (Cai 2007). Such inhibition limits EPSP and protects the neuron from entering a never-ending positive-positive feedback loop between the soma and the dendrites.
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These odorant molecules bind to proteins that keep them dissolved in the mucus and help transport them to the olfactory dendrites. The odorant–protein complex binds to a receptor protein within the cell membrane of an olfactory dendrite. These receptors are G protein–coupled, and will produce a graded membrane potential in the olfactory neurons. The sense of smell Bequest of Mrs E.G. Elgar, 1945 Museum of New Zealand Te Papa Tongarewa.
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This effect is known as shunting inhibition (as opposed to inhibition by hyperpolarization). Illuminating the dendrite prevents the generation of dendritic calcium spikes while illumination of the entire neuron blocks action potential initiation in response to sensory stimulation. Axon terminals, however, have a higher chloride concentration and are therefore excited by ACRs. To inhibit neurons with wide-field illumination, it has proven useful to restrict ACRs to the somatic compartment (ST variants).
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The principal cell type of the dentate gyrus is the granule cell. The dentate gyrus granule cell has an elliptical cell body with a width of approximately 10 μm and a height of 18μm. The granule cell has a characteristic cone-shaped tree of spiny apical dendrites. The dendrite branches project throughout the entire molecular layer and the furthest tips of the dendritic tree end just at the hippocampal fissure or at the ventricular surface.
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Actin remodeling is a biochemical process in cells. In the actin remodeling of neurons, the protein actin is part of the process to change the shape and structure of dendritic spines. G-actin is the monomer form of actin, and is uniformly distributed throughout the axon and the dendrite. F-actin is the polymer form of actin, and its presence in dendritic spines is associated with their change in shape and structure.
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The value of threshold can vary according to numerous factors. Changes in the ion conductances of sodium or potassium can lead to either a raised or lowered value of threshold. Additionally, the diameter of the axon, density of voltage activated sodium channels, and properties of sodium channels within the axon all affect the threshold value. Typically in the axon or dendrite, there are small depolarizing or hyperpolarizing signals resulting from a prior stimulus.
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In Drosophila, studies comprise both larval and adult phases, and number of hours after egg layer is determinant for correct construction of dendritic tiling in sensory neurons. Early in the pupal stage, those neurons prune all their dendrites. Later each neuron grows a completely new dendrite for adult function. While the dendrites are being remodeled, the axons stay largely intactHan S, Song Y, Xiao H, Wang D, Franc NC, Jan LY, Jan YN, 2013.
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Stimuli to neurons can be physical, electrical, or chemical, and can either inhibit or excite the neuron being stimulated. An inhibitory stimulus is transmitted to the dendrite of a neuron, causing hyperpolarization of the neuron. The hyperpolarization following an inhibitory stimulus causes a further decrease in voltage within the neuron below the resting potential. By hyperpolarizing a neuron, an inhibitory stimulus results in a greater negative charge that must be overcome for depolarization to occur.
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Schematic of a chemical synapse between an axon of one neuron and a dendrite of another. Spike-timing-dependent plasticity (STDP) refers to the functional changes in a neuron and its synapse due to time dependent action potentials. When an action potential reaches the pre-synaptic membrane it opens voltage-gated calcium channels causing an influx of calcium. The influx of calcium releases vesicles filled with neurotransmitters, usually glutamate, into the synaptic cleft.
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The SDS model was intended as a computationally simple version of the full Baer and Rinzel model. It was designed to be analytically tractable and have as few free parameters as possible while retaining those of greatest significance, such as spine neck resistance. The model drops the continuum approximation and instead uses a passive dendrite coupled to excitable spines at discrete points. Membrane dynamics in the spines are modelled using integrate and fire processes.
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The AHI keeps detailed data for all results that submit annually to the European Association of Cardiothoracic Surgery (EACS) database. Patient outcomes are monitored using American Association for Thoracic Surgery (AATS) approved software (Axis-Dendrite PATS). The center has performed a series of several high-risk cases with severe left ventricular dysfunction achieving exceptional results. Current outcomes compare favorably with the data published by the STS and the European Association of Cardiothoracic Surgery (EACS).
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Dendrites themselves appear to be capable of plastic changes during the adult life of animals, including invertebrates. Neuronal dendrites have various compartments known as functional units that are able to compute incoming stimuli. These functional units are involved in processing input and are composed of the subdomains of dendrites such as spines, branches, or groupings of branches. Therefore, plasticity that leads to changes in the dendrite structure will affect communication and processing in the cell.
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Some eukaryotes have a second spliceosome, the so-called minor spliceosome. A group of less abundant snRNAs, U11, U12, U4atac, and U6atac, together with U5, are subunits of the minor spliceosome that splices a rare class of pre-mRNA introns, denoted U12-type. The minor spliceosome is located in the nucleus like its major counterpart, though there are exceptions in some specialised cells including anucleate platelets and the dendroplasm (dendrite cytoplasm) of neuronal cells.
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The branching pattern is organized such that certain presynaptic input will have more influence on a given dendrite than others, creating a polarity in excitation and inhibition. Further evidence suggests that starburst cells release inhibitory neurotransmitters, GABA onto each other in a delayed and prolonged manner. This accounts for the temporal property of inhibition. In addition to spatial offset due to GABAergic synapses, the important role of chloride transporters has started to be discussed.
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Illustration of the major elements of neurotransmission. Depending on its method of action, a psychoactive substance may block the receptors on the post-synaptic neuron (dendrite), or block reuptake or affect neurotransmitter synthesis in the pre- synaptic neuron (axon). Psychoactive drugs operate by temporarily affecting a person's neurochemistry, which in turn causes changes in a person's mood, cognition, perception and behavior. There are many ways in which psychoactive drugs can affect the brain.
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Illustration of the major elements in chemical synaptic transmission. An electrochemical wave called an action potential travels along the axon of a neuron. When the wave reaches a synapse, it provokes release of a puff of neurotransmitter molecules, which bind to chemical receptor molecules located in the membrane of another neuron, on the opposite side of the synapse. Schematic of a chemical synapse between an axon of one neuron and a dendrite of another.
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Neurotransmitters are packaged into synaptic vesicles that cluster beneath the axon terminal membrane on the presynaptic side of a synapse. The axonal terminals are specialized to release the neurotransmitters of the presynaptic cell. The terminals release transmitter substances into a gap called the synaptic cleft between the terminals and the dendrites of the next neuron. The information is received by the dendrite receptors of the postsynaptic cell that are connected to it.
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They further observed that the enlarged asynaptic domain is restored partly in UNC-5 which demonstrates that UNC-5 acts cell autonomously in DA9 in order to mediate ectopic UNC-6 exclusion of presynaptic components. The UNC-6 gradient is high ventrally and low dorsally and encompasses the dendrite and ventral axon of DA9. UNC-6 was recently found to cause the initial polarization of the C. elegans hermaphrodite specific neuronal cell body.
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A parasol cell, sometimes called an M cell or M ganglion cell, is one type of retinal ganglion cell (RGC) located in the ganglion cell layer of the retina. These cells project to magnocellular cells in the lateral geniculate nucleus (LGN) as part of the magnocellular pathway in the visual system. They have large cell bodies as well as extensive branching dendrite networks and as such have large receptive fields. Relative to other RGCs, they have fast conduction velocities.
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Likewise, it interacts with cytoplasmic polyadenylation factors, including Cleavage and polyadenylation specificity factor and CPEB, and with target mRNAs. These findings confirm and extend a recent report that a GLD-2 enzyme is the long-sought PAP responsible for cytoplasmic polyadenylation in oocytes. In addition, the formation of long- term memory is believed to lack translational control of localized mRNAs. In mammals, dendrite mRNAs are kept in a repressed state and are activated upon repetitive stimulation.
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Forebrain-specific conditional Ube3b knockout mice showed impaired spatial learning, altered social interactions, and repetitive behaviors. Ube3b knockout neurons exhibited decreased dendritic branching, increased density and aberrant morphology of dendritic spines, altered synaptic physiology, and changes in hippocampal circuit activity. Dendritic and spine phenotype was regulated by Ube3b in a cell-autonomous manner. Murine Ube3b ubiquitinated the catalytic γ-subunit of calcineurin, Ppp3cc, the overexpression of which phenocopied Ube3b loss with regard to dendrite branching and dendritic spine density.
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Because of these phenotypic similarities, there has been research into the specific genetic similarities between these two pervasive developmental disorders. MECP2 has been identified as the predominant gene involved in RTT. It has also been shown that the regulation of the MECP2 gene expression has been implicated in autism. Rett syndrome brain samples and autism brain samples show immaturity of dendrite spines and reduction of cell-body size due to errors in coupled regulation between MECP2 and EGR2.
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Insects have a complex nervous system which incorporates a variety of internal physiological information as well as external sensory information. As in the case of vertebrates, the basic component is the neuron or nerve cell. This is made up of a dendrite with two projections that receive stimuli and an axon, which transmits information to another neuron or organ, like a muscle. As with vertebrates, chemicals (neurotransmitters such as acetylcholine and dopamine) are released at synapses.
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Synapses are specialised minute gaps between neurons. The electrical impulses arriving at the axon terminal triggers the release of packets of chemical messengers (neurotransmitters), which diffuse across the synaptic cleft to receptors on the adjacent dendrite temporarily affecting the likelihood that an electrical impulse will be triggered in the latter neuron. Once released the neurotransmitter is rapidly metabolised or is pumped pack into a neuron. Drawing by Santiago Ramón y Cajal of neurons in the pigeon cerebellum.
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Reelin (RELN) is a large secreted extracellular matrix glycoprotein that helps regulate processes of neuronal migration and positioning in the developing brain by controlling cell–cell interactions. Besides this important role in early development, reelin continues to work in the adult brain. It modulates synaptic plasticity by enhancing the induction and maintenance of long-term potentiation. It also stimulates dendrite and dendritic spine development and regulates the continuing migration of neuroblasts generated in adult neurogenesis sites like the subventricular and subgranular zones.
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Environmental enrichment is concerned with how the brain is affected by the stimulation of its information processing provided by its surroundings (including the opportunity to interact socially). Brains in richer, more-stimulating environments, have increased numbers of synapses, and the dendrite arbors upon which they reside are more complex. This effect happens particularly during neurodevelopment, but also to a lesser degree in adulthood. With extra synapses there is also increased synapse activity and so increased size and number of glial energy-support cells.
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The spine apparatus consists of membranous saccules (discs) and tubules surrounded by wispy filamentous material and is mainly found in large mushroom-shaped dendritic spines. The wispy filamentous material is the cytoskeletal network, mainly f-actin, which is responsible for the maintenance and alteration of spine shape. The spine apparatus is connected to the smooth- surfaced endoplasmic reticulum of the dendrite. Consisting of continuous parallel flattened cisternae, the spine apparatus has a large surface area which is important for its function.
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Stimulated Raman scattering (SRS) microscopy allows non-invasive label-free imaging in living tissue. In this method, pioneered by the Xie group, a construction of an image is obtained by performing SRS measurements over some grid, where each measurement adds a pixel to the image. Recently, SRS imaging starts to appear in material science researches. In 2018, Yang and Min groups at Columbia University used SRS imaging to visualize ion transport in battery electrolyte and its correlation with lithium dendrite growth.
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Mushroom bodies are usually described as neuropils, i.e. as dense networks of neuronal processes (dendrite and axon terminals) and glia. They get their name from their roughly hemispherical calyx, a protuberance that is joined to the rest of the brain by a central nerve tract or peduncle. Most of our current knowledge of mushroom bodies comes from studies of a few species of insect, especially the cockroach Periplaneta americana, the honey bee Apis mellifera, the locust and the fruit fly Drosophila melanogaster.
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Many of the musical collaborations that have resulted have taken on a life beyond the Kraakgeluiden series, which ceased in 2006. La Berge’s own music has evolved in parallel, and the flute has become only one element in a sound world that includes samples, synthesis, the use of spoken text and electronic processing. In 2006 - 2007 she collaborated with Dr. David LaBerge. This is a performance work based on Dr. La Berge's apical dendrite theory using film, narrative voice samples and music.
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Nerve fibers are classed into three types – group A nerve fibers, group B nerve fibers, and group C nerve fibers. Groups A and B are myelinated, and group C are unmyelinated. These groups include both sensory fibers and motor fibers. Another classification groups only the sensory fibers as Type I, Type II, Type III, and Type IV. An axon is one of two types of cytoplasmic protrusions from the cell body of a neuron; the other type is a dendrite.
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The final known associated gene is EFHC1. Myoclonin1/EFHC1 encodes for a protein that has been known to play a wide range of roles from cell division, neuroblast migration and synapse/dendrite formation. EFHC1 is expressed in many tissues, including the brain, where it is localized to the soma and dendrites of neurons, particularly the hippocampal CA1 region, pyramidal neurons in the cerebral cortex, and Purkinje cells in the cerebellum. There are four JME-causing mutations discovered (D210N, R221H, F229L and D253Y).
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Changes of spine density and dendritic complexity in the prefrontal cortex in offspring of mothers exposed to stress during pregnancy. European Journal of Neuroscience. 2006;24:1477–1487. Chronic stress has been shown to reduce the arbor complexity and total dendritic length of apical dendrite trees of CA3 pyramidal neurons in the hippocampus as well.McKittrick CR MA, Blanchard DC, et al. Chronic Social Stress Reduces Dendritic arbors in CA3 of Hippocampus and Decreases Binding to Serotonin Transporter Sites. Synapse. 2000;36:85-942006;24:1477-1487.
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Examples of contemporary Native American beadwork Beadwork is a Native American art form which evolved to mostly use glass beads imported from Europe and recently Asia. Glass beads have been in use for almost five centuries in the Americas. Today a wide range of beading styles flourish. Alongside the widespread popularity of glass beads, bead artists continue incorporating natural items such as dyed porcupine quills, shell such as wampum, and dendrite, and even sea urchin spines in a similar manner as beads.
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Learning by experience occurs through modifications of the structural circuits of the brain. These circuits are composed of many neurons and their connections, called synapses, which occur between the axon of one neuron and the dendrite of another. A single neuron generally has many dendrites which are called dendritic branches, each of which can be synapsed by many axons. Along dendritic branches there can be hundreds or even thousands of dendritic spines, structural protrusions that are sites of excitatory synapses.
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Blocking either this influx or the activation of CaMKII prevents LTP, showing that these are necessary mechanisms for LTP. In addition, profusion of CaMKII into a synapse causes LTP, showing that it is a causal and sufficient mechanism. CaMKII has multiple modes of activation to cause the incorporation of AMPA receptors into the perisynaptic membrane. CAMKII enzyme is eventually responsible for the development of the actin cytoskeleton of neuronal cells and, eventually, for the dendrite and axon development (synaptic plasticity).
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As a result, a lithium anode with a tin interface had a battery life cycle of more than 500 hours at 3 mA/cm2, as opposed to 55 hours without the protective interface. Tin requires minimal amounts of specialized equipment and processing. In a cheaper sodium anode, battery lifetime could be improved from less than 10 to more than 1,700 hours. Another way of preventing dendrite growth in batteries that Archer investigated was the addition of large polymers to the liquid electrolyte.
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Another way of inhibiting dendrite growth that Archer investigated is the incorporation of a porous nanostructured membrane, which prevents the formation of subsurface structures in the lithium electrode. The key nanoscale organic hybrid materials (NOHMs) were formed by grafting polyethylene oxide onto silica, subsequently cross-linked with polypropylene oxide to create strong, porous membranes. The intermediate porosity allows liquid electrolytes to flow but prevents dendrites from passing through. The incorporation of such membranes does not not require significant changes in battery design.
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Purkinje cells are found within the Purkinje layer in the cerebellum. Purkinje cells are aligned like dominos stacked one in front of the other. Their large dendritic arbors form nearly two- dimensional layers through which parallel fibers from the deeper-layers pass. These parallel fibers make relatively weaker excitatory (glutamatergic) synapses to spines in the Purkinje cell dendrite, whereas climbing fibers originating from the inferior olivary nucleus in the medulla provide very powerful excitatory input to the proximal dendrites and cell soma.
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A model view of the synapse Synaptic pruning, a phase in the development of the nervous system, is the process of synapse elimination that occurs between early childhood and the onset of puberty in many mammals, including humans. Pruning starts near the time of birth and continues into the mid-20s. During pruning, both the axon and dendrite decay and die off. It was traditionally considered to be complete by the time of sexual maturation, but this was discounted by MRI studies.
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An example of a pseudofossil: Manganese dendrites on a limestone bedding plane from Solnhofen, Germany; scale in mm Pseudofossils are visual patterns in rocks that are produced by geologic processes rather than biologic processes. They can easily be mistaken for real fossils. Some pseudofossils, such as geological dendrite crystals, are formed by naturally occurring fissures in the rock that get filled up by percolating minerals. Other types of pseudofossils are kidney ore (round shapes in iron ore) and moss agates, which look like moss or plant leaves.
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Wnt7b is a key paracrine signaling factor secreted by the ureteric epithelium that establishes the cortico-medullary axis of the mammalian kidney. Wnt7b is a signaling protein that plays a crucial role for many developmental processes including placental, lung, eye, dendrite, and bone formation along with kidney development. The primary role of Wnt7b is to establish the cortico-medullary axis of epithelial organization. The establishment of the cortico-medullary axis plays an essential role for the development of the medullary component of the kidney.
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His start in physics, in 1934, was through graduate studies on solid state physics under Paul Peter Ewald enabled through a scholarship, at the Technical University of Stuttgart. While there, he started working with Helmut Hönl, who was instrumental in the development of his interest in theory of relativity. In 1935, he earned his PhD there, with a dissertation on Investigations on the dendrite growth of crystals,Papapetrou, A. N. (1935). "Untersuchungen über dendritisches Wachstum von Kristallen", Pries., Zeitschrift für Kristallographie, 92 (1/2), 89-129.
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Dendrodendritic synapses are connections between the dendrites of two different neurons. This is in contrast to the more common axodendritic synapse (chemical synapse) where the axon sends signals and the dendrite receives them. Dendrodendritic synapses are activated in a similar fashion to axodendritic synapses in respects to using a chemical synapse. These chemical synapses receive a depolarizing signal from an incoming action potential which results in an influx of calcium ions that permit release of Neurotransmitters to propagate the signal the post synaptic cell.
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Shunting is an event in the neuron which occurs when an excitatory postsynaptic potential and an inhibitory postsynaptic potential are occurring close to each other on a dendrite, or are both on the soma of the cell.Kandel, E. R., Schwartz, J. H., Jessell, T. M. (2000) [1981]. Principles of Neural Science (Fourth ed.). New York: McGraw-Hill. pp. 217, 223-225 According to temporal summation one would expect the inhibitory and excitatory currents to be summed linearly to describe the resulting current entering the cell.
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In precipitation models, nucleation is generally a prelude to models of the crystal growth process. Sometimes precipitation is rate-limited by the nucleation process. An example would be when someone takes a cup of superheated water from a microwave and, when jiggling it with a spoon or against the wall of the cup, heterogeneous nucleation occurs and most of water particles convert into steam. If the change in phase forms a crystalline solid in a liquid matrix, the atoms might then form a dendrite.
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In cockroaches Blaberus discoidalis and Blattella germanica, the organ has the shape of a fan that is placed across the limb. Much of its volume is filled with discoidal cells that serve accessory purposes; they are placed between an epidermal cell layer attached to the cuticle and connective tissue. Sensory structures called chordotonal sensilla are involved in the perception of movement proper and contain a neuron per sensillum, about 40-50 in total. This neuron has a single dendrite and several cilia extend from it.
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Schematic of friction stir processing. The processed metal is subjected to high strain that modifies its dendrite (grain) pattern – the dendrites are smaller and more round in the nugget zone than in the undeformed regions. Friction stir processing (FSP) is a method of changing the properties of a metal through intense, localized plastic deformation. This deformation is produced by forcibly inserting a non-consumable tool into the workpiece, and revolving the tool in a stirring motion as it is pushed laterally through the workpiece.
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Additionally, these types of materials can achieve up to 135% strain at failure indicating a degree of ductility. Applications that require higher strength ion gel will often use a refractory matrix to generate composite strengthening. This is particularly desirable in lithium-ion battery applications, which seek to deter the growth of lithium dendrites in the cell that can result in an internal short-circuit. A relationship has been established in lithium-ion batteries between high modulus, strong, solid electrolytes and a reduction in lithium dendrite growth.
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Habituation and classical conditioning to light stimuli have been demonstrated, as has the use of brightness and shape information by males when recognizing potential mates. The retinula (literally, "small retina") cells of the ommatidium of the compound eye contain areas from which membranous organelles of conceivable size (rhabdomeres) extend. Rhabdomeres have tiny microvilli (tiny tubes extending out of the retinula) that interlock with neighboring retinular cells. This forms the rhabdom, which contains the dendrite of the eccentric cell, and may also contribute some microvilli.
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Many tiny hair-like cilia protrude from the olfactory receptor cell's dendrite into the mucus covering the surface of the olfactory epithelium. The surface of these cilia is covered with olfactory receptors, a type of G protein-coupled receptor. Each olfactory receptor cell expresses only one type of olfactory receptor (OR), but many separate olfactory receptor cells express ORs which bind the same set of odors. The axons of olfactory receptor cells which express the same OR converge to form glomeruli in the olfactory bulb.
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The Drosophila external sensory organ is a sensory structure in the peripheral nervous system that consists of four cells; a neuron, a sheath cell that surrounds the dendrite, and hair and socket cells, which are considered the “outer” support cells. All four cell fates are descendants of the sensory organ precursor (SOP) cell. In response to the proper cues, SOPs first divide into two secondary precursor cells. The posterior daughter cell is called the pIIa cell and the anterior daughter cell is called the pIIb.
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In the brain, liver X receptor beta is the primary LXR type which interacts with 24S-HC. 24S-HC levels sensed by LXRs can regulate the expression of SREBP mRNA and protein, which in turn regulate cholesterol synthesis and fatty acid synthesis. 24S-HC may participate in several aspects of brain development and function, such as axon and dendrite growth or synaptogenesis. Regulation of 24S-HC metabolism in neurons may play a role in their health and function, as well as their response to injury or disease.
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This decision was appealed by The Suggestion Box and Doe arguing that while the superior court correctly adopted the Cahill standard, it was misapplied in this case. On the other hand, Mobilisa argued that the superior court applied the wrong standard but reached the correct conclusion. Public Citizen, whose amicus brief in the case of Dendrite International, Inc. v. Doe No. 3 had led to the adoption of the balancing test in that case, appeared as amicus curiae urging adoption of the _Dendrite_ approach.
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Micrograph showing a von Economo neuron of the cingulate. HE-LFB stain. Von Economo neurons (VENs), also called spindle neurons, are a specific class of mammalian cortical neurons characterized by a large spindle-shaped soma (or body) gradually tapering into a single apical axon (the ramification that transmits signals) in one direction, with only a single dendrite (the ramification that receives signals) facing opposite. Other cortical neurons tend to have many dendrites, and the bipolar-shaped morphology of von Economo neurons is unique here.
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The mechanism for LTP has long been a topic of debate, but, recently, mechanisms have come to some consensus. AMPARs play a key role in this process, as one of the key indicators of LTP induction is the increase in the ratio of AMPAR to NMDARs following high-frequency stimulation. The idea is that AMPARs are trafficked from the dendrite into the synapse and incorporated through some series of signaling cascades. AMPARs are initially regulated at the transcriptional level at their 5’ promoter regions.
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The description of the fossil assemblage together with their mode of occurrence, the cause of sudden death, ecological conditions and chronological position form part of Misra's detailed thesis submitted for the degree of Master of Science. The discovery was reported in a 1968 letter to Nature. Misra described the Mistaken Point fauna in detail in 1969, in a paper published in the Bulletin of the Geological Society of America. He sorted the fossil assemblage into five groups, namely spindle-shaped, leaf-shaped, round lobate, dendrite like, and radiating.
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The nervous system is the system of neurons, or nerve cells, that relay electrical signals through the brain and body. A nerve cell receives signals from other nerve cells through tree-branch-like extensions called dendrites and passes signals on through a long extension called an axon (or nerve fiber). Synapses are places where one cell's axon passes information to another cell's dendrite by sending chemicals called neurotransmitters across a small gap called a synaptic cleft. Synapses occur in various locations, including ganglia (singular: ganglion), which are masses of nerve cell bodies.
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This idea reflects the fact the longer the linked destinations the higher the level of mobility must be. A dendrite configuration, such as a river, takes progressively wider expanses of land to accommodate the flow. A nested hierarchyMarshall, S. (2005) Streets And Patterns: The Structure of Urban Geometry (London and New York: Spon Press) Chapter 7 on the other hand distributes the flow at each volume level to alternative paths. The complete system, though it may appear unfamiliar, is composed of entirely familiar and extensively used elements in contemporary development.
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The way that synaptic potential is created involves the theories behind potential difference and current through a conductor. When an action potential fires at the dendritic spine where the action potential is initiated from the presynaptic terminal to the post synaptic terminal. This action potential is then carried down the length of the dendrite and then is propagated down the length of the axon inn order to get the presynaptic terminal to then perpetuate the process. The way that this process actually occurs is more complex than it may seem at first glance.
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Apart from the source of the confidential loan documents, Mortgage Specialists also sought the identity of Brianbattersby, whose posting were allegedly defamatory. The trial court had originally required that Implode comply with Mortgage Specialists' request. The Supreme Court adopted the Dendrite test, holding that "the qualified privilege to speak anonymously requires the trial court to 'balanc[e] ... the equities and rights at issue,' thus ensuring that a plaintiff alleging defamation has a valid reason for piercing the speaker's anonymity." The court then vacated the trial court's decision and remanded the case on this issue.
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The egl-20::unc-6 transgene creates an enlarged asynaptic zone of the DA9 dorsal axon. They further observed that the enlarged asynaptic domain is restored partly in UNC-5 which demonstrates that UNC-5 acts cell autonomously in DA9 in order to mediate ectopic UNC-6 exclusion of presynaptic components. The UNC-6 gradient is high ventrally and low dorsally and encompasses the dendrite and ventral axon of DA9. UNC-6 was recently found to cause the initial polarization of the C. elegans hermaphrodite specific neuronal cell body.
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Increases in cpg15 expression caused changes in axon and dendrite growth, as well as synapse formation. Harwell and his colleague Ulrich Putz showed that expression of a soluble form of CPG15 promoted survival of cortical neuron progenitors in early brain development. Additionally, Harwell, with members of Karel Svoboda's group, demonstrated that cpg15 expression in adult mice could be diminished by sensory deprivation, raising the possibility that CPG15 functions in a neural activity-dependent manner. After receiving his PhD, Harwell completed a postdoctoral fellowship in Arnold Kriegstein's laboratory at the University of California, San Francisco.
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In watercolours, Endel Ruberg discovered a technique to produce naturally occurring frost patterns in his paintings—the akvarelli külmutustehnika (an Estonian expression meaning watercolour freeze technique). The akvarelli külmutustehnika relies on painting outdoors during winter, allowing the cold air to condense and crystallize the watercolour paints as they dry. In those cold working conditions Ruberg painted with urgency, his brushwork displaying a fluid and spontaneous style. The akvarelli külmutustehnika introduces unpredictable geometric patterns, which appear as dendrite formations, needle-like structures, and arrow-like patterns depending on the wind conditions.
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Postsynaptic NMDA receptors are highly sensitive to the membrane potential (see coincidence detection in neurobiology). Due to their high permeability for calcium, they generate a local chemical signal that is largest when the back-propagating action potential in the dendrite arrives shortly after the synapse was active (pre- post spiking). Large postsynaptic calcium transients are known to trigger synaptic potentiation (Long-term potentiation). The mechanism for spike- timing-dependent depression is less well understood, but often involves either postsynaptic voltage-dependent calcium entry/mGluR activation, or retrograde endocannabinoids and presynaptic NMDARs.
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The electrotonic potential travels via electrotonic spread, which amounts to attraction of opposite- and repulsion of like-charged ions within the cell. Electrotonic potentials can sum spatially or temporally. Spatial summation is the combination of multiple sources of ion influx (multiple channels within a dendrite, or channels within multiple dendrites), whereas temporal summation is a gradual increase in overall charge due to repeated influxes in the same location. Because the ionic charge enters in one location and dissipates to others, losing intensity as it spreads, electrotonic spread is a graded response.
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For a pure material, latent heat is released at the solid–liquid interface so that the temperature remains constant until the melt has completely solidified. The growth rate of the resultant crystalline substance will depend on how fast this latent heat can be conducted away. A dendrite growing in an undercooled melt can be approximated as a parabolic needle-like crystal that grows in a shape- preserving manner at constant velocity. Nucleation and growth determine the grain size in equiaxed solidification while the competition between adjacent dendrites decides the primary spacing in columnar growth.
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Sodium channels and dendritic spike initiation at excitatory synapses in globus pallidus neurons. Journal of Neuroscience 24:329-40 It has also been demonstrated through dendritic computational models that the threshold amplitude of a synaptic conductance needed to generate a dendritic spike is significantly less if the voltage-gated sodium channels are clustered at the synapse. The same type of voltage-gated channels may differ in distribution between the soma and dendrite within the same neuron. There seems to be no general pattern of distribution for voltage-gated channels within dendrites.
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Court of Appeals of Maryland, Feb. 27, 2009, No. 63 (pdf). Retrieved on 2009-03-15. After reviewing the treatment of anonymous online speech by other state and federal courts, the Maryland court concluded that "a test requiring notice and opportunity to be heard, coupled with a showing of a prima facie case and the application of a balancing test—such as the standard set forth in Dendrite—most appropriately balances a speaker's constitutional right to anonymous Internet speech with a plaintiff's right to seek judicial redress from defamatory remarks."Id.
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In mathematics, a unicoherent space is a topological space X that is connected and in which the following property holds: For any closed, connected A, B \subset X with X=A \cup B, the intersection A \cap B is connected. For example, any closed interval on the real line is unicoherent, but a circle is not. If a unicoherent space is more strongly hereditarily unicoherent (meaning that every subcontinuum is unicoherent) and arcwise connected, then it is called a dendroid. If in addition it is locally connected then it is called a dendrite.
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Pyramidal cells are the majority class of cells in the neocortex. They have high density of dendritic spines, prominent apical dendrites, and axons that project out of the cortex as well as locally within it. Soma for these appear in all layers except I. Spiny stellate cells are distinguished from pyramidal cells here by the absence of the apical dendrite and the fact that their axons also do not leave the cortex. These cells are thought to begin as pyramidal neurons and then retract their apical dendrites and axons.
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The description of the fossil assemblage together with their mode of occurrence, the cause of sudden death, ecological conditions and chronological position form part of Misra's detailed thesis submitted for a degree of Master of Science. The discovery was reported in a 1968 letter to Nature. Misra described the Mistaken Point fauna in detail in 1969, in a paper published in the Bulletin of the Geological Society of America. He sorted the fossil assemblage into five groups, namely spindle-shaped, leaf-shaped, round lobate, dendrite like, and radiating.
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277px During the development of dendrites, several factors can influence differentiation. These include modulation of sensory input, environmental pollutants, body temperature, and drug use. For example, rats raised in dark environments were found to have a reduced number of spines in pyramidal cells located in the primary visual cortex and a marked change in distribution of dendrite branching in layer 4 stellate cells. Experiments done in vitro and in vivo have shown that the presence of afferents and input activity per se can modulate the patterns in which dendrites differentiate.
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NWs are an attractive as they are highly functional structures that offer unique electronic properties that are affected by biological/chemical species adsorbed on their surface; mostly the conductivity. This conductivity variance depending on chemical species present allows enhanced sensing performances. NWs are also able to act as non- invasive and highly local probes. These versatility of NWs makes it optimal for interfacing with neurons due to the fact that the contact length along the axon (or the dendrite projection crossing a NW) is just about 20 nm.
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The zinc-polyiodide battery is claimed to be safer than other flow batteries given its absence of acidic electrolytes, nonflammability and operating range of that does not require extensive cooling circuitry, which would add weight and occupy space. One unresolved issue is zinc build-up on the negative electrode that permeated the membrane, reducing efficiency. Because of the Zn dendrite formation, the Zn-halide batteries cannot operate at high current density (>20 mA/cm2) and thus have limited power density. Adding alcohol to the electrolyte of the ZnI battery can slightly control the problem.
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Research has shown that removal of the olfactory bulb in rats leads to dendrite reorganization, disrupted cell growth in the hippocampus, and decreased neuroplasticity in the hippocampus. These hippocampal changes due to olfactory bulb removal are associated with behavioral changes characteristic of depression, demonstrating the correlation between the olfactory bulb and emotion. The hippocampus and amygdala affect odor perception. During certain physiological states such as hunger a food odor may seem more pleasant and rewarding due to the associations in the amygdala and hippocampus of the food odor stimulus with the reward of eating.
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The popular hypothesis is that starburst amacrine cells differentially express chloride transporters along the dendrites. Given this assumption, some areas along the dendrite will have a positive chloride-ion equilibrium potential relative to the resting potential while others have a negative equilibrium potential. This means that GABA at one area will be depolarizing and at another area hyperpolarizing, accounting for the spatial offset present between excitation and inhibition. Recent research (published March 2011) relying on serial block-face electron microscopy (SBEM) has led to identification of the circuitry that influences directional selectivity.
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Donald Hebb theorized that strengthening of synaptic connections occurred because of coordinated activity between the pre-synaptic terminal and post- synaptic dendrite. According to Hebb, these two cells are strengthened because their signaling occurs together in space and/or time, also known as coincident activity. This postulate is often summarized as Cells that fire together, wire together, which means that the synapses that have neurons with coincident firing are strengthened, while the other synapses on these neurons remain unchanged. Hebb's postulate has provided a conceptual framework for how synaptic plasticity underlies long-term information storage.
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Amacrine cells operate at inner plexiform layer (IPL), the second synaptic retinal layer where bipolar cells and retinal ganglion cells form synapses. There are at least 33 different subtypes of amacrine cells based just on their dendrite morphology and stratification. Like horizontal cells, amacrine cells work laterally, but whereas horizontal cells are connected to the output of rod and cone cells, amacrine cells affect the output from bipolar cells, and are often more specialized. Each type of amacrine cell releases one or several neurotransmitters where it connects with other cells.
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A third way is to hypothesize a theory of the functioning of the biological components of the neural system by a mathematical model, in the form of a set of mathematical equations. The variables of the equation are some or all of the neurobiological properties of the entity being modeled, such as the dimensions of the dendrite or the stimulation rate of action potential along the axon in a neuron. The mathematical equations are solved using computational techniques and the results are validated with either simulation or experimental processes. This approach to modeling is called computational neuroscience.
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BDNF levels appear to be highly regulated throughout the lifetime both in the early developmental stages and in the later stages of life. For example, BDNF appears to be critical for the morphological development such as dendrite orientation and number along with soma size. This is important as neuron morphology is critical in behavioral processes like learning and motor skills development. Research has reported that the interaction between BDNF and TrkB (the receptor to BDNF) is highly important in inducing dendritic growth; some have noted that the phosphorylation of TrkB by another molecule, cdk5 is necessary for this interaction to occur.
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Dendritic spines usually receive excitatory input from axons, although sometimes both inhibitory and excitatory connections are made onto the same spine head. Excitatory axon proximity to dendritic spines is not sufficient to predict the presence of a synapse, as demonstrated by the Lichtman lab in 2015. Spines are found on the dendrites of most principal neurons in the brain, including the pyramidal neurons of the neocortex, the medium spiny neurons of the striatum, and the Purkinje cells of the cerebellum. Dendritic spines occur at a density of up to 5 spines/1 μm stretch of dendrite.
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Both the presynaptic and postsynaptic sites contain extensive arrays of molecular machinery that link the two membranes together and carry out the signaling process. In many synapses, the presynaptic part is located on an axon and the postsynaptic part is located on a dendrite or soma. Astrocytes also exchange information with the synaptic neurons, responding to synaptic activity and, in turn, regulating neurotransmission. Synapses (at least chemical synapses) are stabilized in position by synaptic adhesion molecules (SAMs) projecting from both the pre- and post-synaptic neuron and sticking together where they overlap; SAMs may also assist in the generation and functioning of synapses.
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Several patterns in activity control the development of the brain. Action potential changes in the retina, hippocampus, cortex, and spinal cord provide activity-based signals both to the active neurons and their post-synaptic target cells. Spontaneous activity originating within neuronal gap junctions, the cortex sub-plate, and sensory inputs are all involved in the cell signaling that regulates dendrite growth. Useful models of dendritic arbor formation are the Xenopus tadpoles, which are transparent in early stages of larval development and allow for dye-labeled neurons to be repeatedly imaged in the intact animal over several weeks.
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A rodent is not stimulated by the environment in a wire cage, and this affects its brain negatively, particularly the complexity of its synaptic connections Environmental enrichment is the stimulation of the brain by its physical and social surroundings. Brains in richer, more stimulating environments have higher rates of synaptogenesis and more complex dendrite arbors, leading to increased brain activity. This effect takes place primarily during neurodevelopment, but also during adulthood to a lesser degree. With extra synapses there is also increased synapse activity, leading to an increased size and number of glial energy-support cells.
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Both of these drugs induce increased locomotor activity acutely, escalated self- administration chronically, and dysphoria when the drug is taken away. Although their effects on structural plasticity are opposite, there are two possible explanations as to why these drugs still produce the same indicators of addiction: Either these changes produce the same behavioral phenotype when any change from baseline is produced, or the critical changes that cause the addictive behavior cannot be quantified by measuring dendritic spine density. Opiates decrease spine density and dendrite complexity in the nucleus accumbens (NAc). Morphine decreases spine density regardless of the treatment paradigm.
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It makes the C-start response behaviorally important as a way to initiate the escape reflex in an all or nothing fashion, while the direction and speed of the escape can be corrected later through the activity of smaller motor neurons. In larval zebrafish about ~60% of the total population of reticulospinal neurons are also activated by a stimulus that elicits the M-spike and C-start escape. A well-studied group of these reticulospinal neurons are the bilaterally paired M-cell homologues denoted MiD2cm and MiD3cm. These neurons exhibit morphological similarities to the M-cell including a lateral and ventral dendrite.
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The canister on the left is whipped cream, a product which is pressurized with nitrous oxide. Glue and gasoline (petrol) sniffing is also a problem in parts of Africa, especially with street children. In India and South Asia, three of the most widely abused inhalants are the Dendrite brand and other forms of contact adhesives and rubber cements manufactured in Kolkata, and toluenes in paint thinners. Genkem is a brand of glue which had become the generic name for all the glues used by glue-sniffing children in Africa before the manufacturer replaced n-hexane in its ingredients in 2000.
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Over the years battery voltages have increased, with 18 V drills being most common, but higher voltages are available, such as 24 V, 28 V, and 36 V. This allows these tools to produce as much torque as some corded drills. Common battery types of are nickel-cadmium (NiCd) batteries and lithium-ion batteries, with each holding about half the market share. NiCd batteries have been around longer, so they are less expensive (their main advantage), but have more disadvantages compared to lithium-ion batteries. NiCd disadvantages are limited life, self-discharging, environment problems upon disposal, and eventually internally short circuiting due to dendrite growth.
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Dendritic cell. The classification of dendritic cells as another type of white blood cell occurred over thirty-five years ago by Ralph Steinmann and Zanvil A. Cohn and has provided an essential link in the innate immune system. Dendritic cells line airways and intestines, participate in a rich network making up part of the epidermal layer of the skin, and play a unique role in initiating a primary immune response. Dendritic cells are named after their structure that resembles that of a dendrite of an axon, and they have two vital functions: display antigens, which are recognized by T cells and alert lymphocytes of the presence of an injury or infection.
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Aspiny neurons, the second class of neurons found in the stratum lucidum, are another type of inhibitory cell similar to spiny neurons, though lacking dendrite projections. They make up the majority of the neuron composition in comparison to spiny neurons, about 63 percent. The somata of aspiny neurons are for the most part bipolar, generating 2–5 primary dendrites "that to a varying extent displayed varicose swellings in their course". Similar to spiny neurons, aspiny neuron dendrites "branch extensively in stratum lucidum and stratum radiatum of CA3", in contrast to spiny neurons, however, some dendrites "traversed stratum pyramidale and entered stratum oriens", the second deepest layer of the hippocampus.
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The plot revolved around three detectives for hire: the group's leader Mastermind, who wore a white Nehru jacket and as his name implied was the brains of the operation; Kittka, a female escape artist who wore a skintight blue tuxedo and had blue hair and skin; and Samson, a large, muscular man in a black suit. Their many foes during the 10 three- minute episodes included an evil crime clown, an intergalactic poodle conspiracy, an evil genius (and rival of Mastermind's) named Dr. Raoul Dendrite and his schoolgirl-uniformed assistant Delilah, and Negator, who subdued his opponents with a highly sarcastic wit (and aided by a Don Rickles mask).
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In a short section (perhaps 40 µm long) of distal dendrite, the reaction to activations coming in on synapses to the dendritic spines acts to raise the overall local potential with each incoming signal. This rising potential acts against a background of decay in the potential back to the resting level. If sufficient signals are received within a short period of time (i.e. before the overall voltage decays to background), the voltage of the segment will rise above a threshold, giving rise to a non-linear dendritic spike, which travels, effectively undiminished, all the way to the cell body, and which causes it to become partially depolarised.
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More neurotransmitter is released from the activated mitral cell to the connected dendrite of the granule cell, making the inhibitory effect from the granule cell to the activated mitral cell stronger than the surrounding mitral cells. It is not clear what the functional role of lateral inhibition would be, though it may be involved in boosting the signal-to-noise ratio of odor signals by silencing the basal firing rate of surrounding non-activated neurons. This in turn aids in odor discrimination. Other research suggest that the lateral inhibition contributes to differentiated odor responses, which aids in the processing and perception of distinct odors.
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Mitral cells are a neuronal cell type in the mammalian olfactory bulb, distinguished by the position of their somata located in an orderly row in the mitral cell layer of the bulb. They typically have a single primary dendrite, which they project into a single glomerulus in the glomerular layer, and a few lateral dendrites that project laterally in the external plexiform layer. Mitral cells are closely related to the second type of projection neuron in the mammalian bulb, known as the tufted cell. In lower vertebrates, mitral and tufted cells cannot be morphologically distinguished from tufted cells, and their morphology is substantially different from the mammalian mitral cells.
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It appears that tufted cells receive strong olfactory nerve input, fire close to inhalation onset and their firing phase is relatively concentration insensitive, whereas mitral cells receive relatively weak olfactory nerve input and strong periglomerular inhibition, which delays their firing relative to the tufted cells. This escape from inhibition can be sped up by increasing the stimulating odorant concentration, and thus mitral cell firing phase acts as one possible way the olfactory system encodes concentration. The role of the mitral cell lateral dendrite and granule cell circuit is currently a bit more uncertain. One possible hypothesis implicates the system in forming sparse representation which enable more effective pattern separation.
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Archer discovered that adding certain halide salts to liquid electrolytes creates nanostructured surface coatings on lithium battery anodes that hinder the development of dendritic structures that grow within the battery cell and typically lead to a decline in performance and overheating. This study was conducted by modeling metal electrodeposition using density functional theory and continuum mechanics. By adding tin to a carbonate-based electrolyte, Archer's group observed the instantaneous formation of a nanometer-thick interface that shields the anode and prevents dendrite formation, but keeps it electrochemically active. Lithium can rapidly alloy with the added tin, which makes the lithium deposition during recharging more uniform.
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A Few of the Various Types of Synapses In classic brain theory the summation of electrical inputs to the dendrites and soma (cell body) of a neuron either inhibit the neuron or excite it and set off an action potential down the axon to where it synapses with the next neuron. However, this fails to account for different varieties of synapses beyond the traditional axodendritic (axon to dendrite). There is evidence for the existence of other kinds of synapses, including serial synapses and those between dendrites and soma and between different dendrites. Many synaptic locations are functionally bipolar, meaning they can both send and receive impulses from each neuron, distributing input and output over the entire group of dendrites.
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ApoER2 gene is alternatively spliced, with the exon 19-containing variant more actively produced during periods of activity. According to one study, the hippocampal reelin expression rapidly goes up when there is need to store a memory, as demethylases open up the RELN gene. The activation of dendrite growth by reelin is apparently conducted through Src family kinases and is dependent upon the expression of Crk family proteins, consistent with the interaction of Crk and CrkL with tyrosine-phosphorylated Dab1. Moreover, a Cre-loxP recombination mouse model that lacks Crk and CrkL in most neurons was reported to have the reeler phenotype, indicating that Crk/CrkL lie between DAB1 and Akt in the reelin signaling chain.
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The axons from dopamine neurons emanate from a primary dendrite and project ipsilaterally (on the same side) via the medial forebrain bundle to the dorsal striatum. There is a rough topographical correlation between the anatomical localization of the dopamine cell body within the SNc and the area of termination in the dorsal striatum. Dopaminergic cells in the lateral parts of the SNc project mainly to the lateral and caudal (posterior) parts of the striatum, whereas dopamine cells in the medial SNc project to the medial striatum. In addition, dopamine cells in the dorsal tier project to the ventromedial striatum, whereas the ventral tier neurons project to the dorsal caudate nucleus and putamen.
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The Elongator Protein Complex (ELP) is what regulates the growth of cortical projection neurons. This means that it helps cortical neurons to exhibit dendrite branching and radial migration of neurons to form the close knit neural network of the cerebral cortex. If ELP is not working properly or is not being expressed at the correct levels (too low) then the neurons in that region in particular would not be properly situated in relation to each other for proper brain activity. The expression of ELP and the fourth sub-unit (ELP4) in particular is the cause of Rolandic epilepsy and possibly other cognitive impairment later in life if the condition is severe enough or if it is not treated effectively.
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Since the end of World War II, new subdivisions in the United States and Canada, as well as New Towns in England and other countries have made extensive use of the cul-de-sac and crescent (loops) street types. Typically, there is one or several central roads in the subdivision with many cul-de-sac streets of varying length, branching out from the main roads, to fill the land in the subdivision, a dendrite or hierarchical pattern. Since the 1960s, the pattern has been the dominant road network structure of suburbs and exurbs in the United States, Canada, and Australia. It is also increasingly popular in Latin America, Western Europe, and China.
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Correct assembly of the components in mice retina is dependent of Dscam/DscamL1 correct expression to form mosaics of different cell type of RGC, soma spacing and dendrite arborization, thus ensuring the coverage of all visual area by each cell type and more specifically to inhibit excessive fasciculation and clumping of cell bodies in photoreceptors, rod bipolar cells (RBCs) and amacrine cells in visual system. The occurrence of correct stratification and connection with synapses tells us that Dscam knockout affects only the repulsive interactions and coverage of the dendritic arbors and functional bindings are maintained.Huberman AD, 2009. Mammalian DSCAMs: They Won't Help You Find a Partner, but They'll Guarantee You Some Personal Space.
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Therefore, the direct isoform-specific homophilic Dscam-Dscam interactions must result in signal transduction events that lead to repulsion of dendrites expressing identical Dscam isoforms. This conversion of an initial Dscam-dependent cell- surface interaction into a repulsive response that leads to dendrite separation in da neurons is supported by Matthews et al. (2007) in a study that demonstrated that the ectopic expression of identical Dscam isoforms on the dendrites of different cells promoted growth away from each other. The authors also suggest that identical Dscam isoforms expressed in two cell populations in vitro induced their aggregation in an isoform-specific manner, showing that Dscam provides cells with the ability to distinguish between different cell surfaces.
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A signal propagating down an axon to the cell body and dendrites of the next cell left Neurons communicate with each other via synapses, where either the axon terminal of one cell contacts another neuron's dendrite, soma or, less commonly, axon. Neurons such as Purkinje cells in the cerebellum can have over 1000 dendritic branches, making connections with tens of thousands of other cells; other neurons, such as the magnocellular neurons of the supraoptic nucleus, have only one or two dendrites, each of which receives thousands of synapses. Synapses can be excitatory or inhibitory, either increasing or decreasing activity in the target neuron, respectively. Some neurons also communicate via electrical synapses, which are direct, electrically conductive junctions between cells.
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A balance between metabolic costs of dendritic elaboration and the need to cover receptive field presumably determine the size and shape of dendrites. A complex array of extracellular and intracellular cues modulates dendrite development including transcription factors, receptor-ligand interactions, various signaling pathways, local translational machinery, cytoskeletal elements, Golgi outposts and endosomes. These contribute to the organization of the dendrites on individual cell bodies and the placement of these dendrites in the neuronal circuitry. For example, it was shown that β-actin zipcode binding protein 1 (ZBP1) contributes to proper dendritic branching. Other important transcription factors involved in the morphology of dendrites include CUT, Abrupt, Collier, Spineless, ACJ6/drifter, CREST, NEUROD1, CREB, NEUROG2 etc.
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Drawing by Camillo Golgi of a hippocampus stained with the silver nitrate method Drawing of a Purkinje cell in the cerebellum cortex done by Santiago Ramón y Cajal, clearly demonstrating the power of Golgi's staining method to reveal fine detail A human neocortical pyramidal neuron stained via Golgi technique. Notice the apical dendrite extending vertically above the soma and the numerous basal dendrites radiating laterally from the base of the cell body. Golgi's method is a silver staining technique that is used to visualize nervous tissue under light microscopy. The method was discovered by Camillo Golgi, an Italian physician and scientist, who published the first picture made with the technique in 1873.
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Disrupted in schizophrenia 1 is a protein that in humans is encoded by the DISC1 gene. In coordination with a wide array of interacting partners, DISC1 has been shown to participate in the regulation of cell proliferation, differentiation, migration, neuronal axon and dendrite outgrowth, mitochondrial transport, fission and/or fusion, and cell-to-cell adhesion. Several studies have shown that unregulated expression or altered protein structure of DISC1 may predispose individuals to the development of schizophrenia, clinical depression, bipolar disorder, and other psychiatric conditions. The cellular functions that are disrupted by permutations in DISC1, which lead to the development of these disorders, have yet to be clearly defined and are the subject of current ongoing research.
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These RNA transcripts containing G4C2 repeats were shown to bind and separate a wide variety of proteins, including nucleolin. Nucleolin is involved in the synthesis and maturation of ribosomes within the nucleus, and separation of nucleolin by the mutated RNA transcripts impairs nucleolar function and ribosomal RNA synthesis. Fragile X mental retardation protein (FMRP) is a widely expressed protein coded by the FMR1 gene that binds to G-quadruplex secondary structures in neurons and is involved in synaptic plasticity. FMRP acts as a negative regulator of translation, and its binding stabilizes G-quadruplex structures in mRNA transcripts, inhibiting ribosome elongation of mRNA in the neuron's dendrite and controlling the timing of the transcript's expression.
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Magnesium is under research as a possible replacement or improvement on lithium-ion battery in certain applications: In comparison to lithium as an anode material magnesium has a (theoretical) energy density per unit mass under half that of lithium (18.8 MJ/kg vs. 42.3 MJ/kg), but a volumetric energy density around 50% higher (32.731 GJ/m3 vs. 22.569 GJ/m3). In comparison to metallic lithium anodes, magnesium anodes do not exhibit dendrite formation, which may allow magnesium metal to be used without an intercalation compound at the anode; the ability to use a magnesium anode without an intercalation layer raises the theoretical maximum relative volumetric energy density to around 5 times that of a lithium ion cell.
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Archer's group found that such a porous electrolyte effectively lengthens the route along which ions travel between anode and cathode and thus increases the life of the anode. Additionally, the porous polymer membrane is softer than the metal, but can nonetheless act as an effective separator suppressing dendritic growth due to its tortuos nanostructure. Archer investigated how tethering anions to the separator membrane in a battery can stabilize an electrochemical cell, which uses reactive metals as electrodes. The electric field at the metal electrode is reduced, which enhances stability during battery recharging even at higher currents, where usually a depletion zone forms due to ion migration, which in turn initiates dendrite growth.
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Since the 1950s, evidence has existed that neurons in the central nervous system generate an action potential, or voltage spike, that travels both through the axon to signal the next neuron and backpropagates through the dendrites sending a retrograde signal to its presynaptic signaling neurons. This current decays significantly with travel length along the dendrites, so effects are predicted to be more significant for neurons whose synapses are near the postsynaptic cell body, with magnitude depending mainly on sodium-channel density in the dendrite. It is also dependent on the shape of the dendritic tree and, more importantly, on the rate of signal currents to the neuron. On average, a backpropagating spike loses about half its voltage after traveling nearly 500 micrometres.
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Increases in pedestrian and bicycle permeability may result in a displacement of local car trips for short distance destinations and consequently a reduction in neighbourhood vehicle emissions. The impermeable cul-de-sac not only discourages walking and biking but also increases the length of car trips by the circuitous geometry of the dendrite network structure of which it is a part. Research studies examined the influence of several variables on the amount of car travel that residents of several types of districts recorded. Results vary considerably among them, but there is general agreement on a number of key correlations:Taming the Flow—Better Traffic and Safer Neighbourhoods. Canada Mortgage and Housing Corporation, July 2008Greenhouse Gas Emissions from Urban Travel: Tool for Evaluating Neighbourhood Sustainability.
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Betz cells are upper motor neurons that send their axons down to the spinal cord via the corticospinal tract, where in humans they synapse directly with anterior horn cells, which in turn synapse directly with their target muscles. While Betz cells have one apical dendrite typical of pyramidal neurons, they have more primary dendritic shafts, which can branch out at almost any point from the soma (cell body). These perisomatic (around the cell body) and basal dendrites project into all cortical layers, but most of their horizontal branches/arbors populate layers V and VI, some reaching down into the white matter. According to one study, Betz cells represent about 10% of the total pyramidal cell population in layer Vb of the human primary motor cortex.
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The EPSPs that converge on the pyramidal neurons through direct afferent fibers ending in the upper part of the apical dendrites cause a flow of charged ions (a current) between points at different potentials within and outside neurons. The positive ions then enter the cell following concentration and electrical charge gradient and propagate to the rest of the neuron. EPSPs from the distal apical dendrites create a current starting from the apical part nearest to the synapse (where the magnitude is greater) toward the cell body because the resistance to this flow is less. The current perpendicular (or radial) to the apical dendrite is accompanied by a magnetic field that propagates orthogonally (or tangentially) to the current along the extracellular side of the cell membrane.
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Furthermore, scientists performed Morris Water Maze tests on mouse and found that anserine treated mouse had overall better spatial memory. The effects of anserine and carnosine were also observed in humans; One study done with 84 elders in Tokyo found that elders who took 500mg of anserine and carnonsine for one year showed more blood flow in the prefrontal cortex through the MRI. There has also been study revealing that free N-terminal of histidine on anserine and carnosine protect against zinc-caused neurotoxicity and regulate Arc pathway in which Arc protein is used to produce dendrite protein for connecting nerve cells. The pKa of the imidazole ring of histidine, when contained in anserine, is 7.04, making it an effective buffer at physiologic pH.
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The interior edges of a hoppered crystal still show the crystal form characteristic to the specific mineral, and so appear to be a series of smaller and smaller stepped down miniature versions of the original crystal. Hoppering occurs when electrical attraction is higher along the edges of the crystal; this causes faster growth at the edges than near the face centers. This attraction draws the mineral molecules more strongly than the interior sections of the crystal, thus the edges develop more quickly. However, the basic physics of this type of growth is the same as that of dendrites but, because the anisotropy in the solid–liquid inter-facial energy is so large, the dendrite so produced exhibits a faceted morphology.
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A later similar comparative traffic study of about concluded that all types of layouts perform adequately in most land use scenarios and that a refined hierarchical, dendrite network can improve traffic performance. Anecdotal and research evidence suggests that navigation (especially on foot) in a disconnected network of cul-de-sac and looped streets is inconvenient and non-intuitive, particularly when combined with curvilinear geometry. Loss of orientation and sense of direction is also a common experience in older cities with cul-de-sac streets (Medina of Arab cities or Mediterranean hill towns) as well as in cities with highly irregular block geometries and sizes and corresponding street alignments that produce a labyrinthine effect. The long history of such cities implies that an irregular, complicated street network that appears entirely illegible to a visitor is well understood and used by the inhabitants.
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Mitral cells receive excitatory input from olfactory sensory neurons and external tufted cells on their primary dendrites, whereas inhibitory input arises either from granule cells onto their lateral dendrites and soma or from periglomerular cells onto their dendritic tuft. Mitral cells together with tufted cells form an obligatory relay for all olfactory information entering from the olfactory nerve. Mitral cell output is not a passive reflection of their input from the olfactory nerve. In mice, each mitral cell sends a single primary dendrite into a glomerulus receiving input from a population of olfactory sensory neurons expressing identical olfactory receptor proteins, yet the odor responsiveness of the 20-40 mitral cells connected to a single glomerulus (called sister mitral cells) is not identical to the tuning curve of the input cells, and also differs between sister mitral cells.
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Synaptic scaling is a post-synaptic homeostatic plasticity mechanism that takes place with changes in the quantity of AMPA receptors at a post-synaptic terminal (the tip of the dendrite belonging to the post-synaptic neuron that meets with the tip of an axon belonging to the pre-synaptic neuron) of a neuron. This closed-loop process gives a neuron the ability to have global negative feedback control of synaptic strength of all its synaptic connections by altering the probability of glutamate (the most common excitatory neurotransmitter) making contact with post-synaptic AMPA receptors. Therefore, a neuron's ability to modulate the quantity of post-synaptic AMPA receptors gives it the ability to achieve a set action potential firing rate. The probability of glutamate making contact with a post-synaptic AMPA receptor is proportional to the concentration of both trans-membrane glutamate and post-synaptic AMPA receptors.
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The second, focused on trails and greenbelts, found that other amenities including cul-de- sac streets add significantly to the home value. The positive feelings that a cul-de-sac street could evoke, that residents value, are expressed vividly by Allan Jacobs in describing Roslyn Place, a short (), narrow (), densely built (), and wood-paved cul-de-sac in the Shadyside neighborhood of Pittsburgh, Pennsylvania: "Step into Roslyn Place and you are likely to sense, immediately, that you are in a place, a special place, a handsome place, a safe place, a welcoming place, a place where you might wish to live." "..."narrowness and enclosure and intimacy bring a feeling of safety to Roslyn Place... “Stay on our street” is all the kids have to know. Gated communities, whose numbers steadily increase worldwide, use cul-de-sac and loop street networks because the dendrite structure reduces the number of through roads and thus the corresponding number of entries and exits that need to be controlled.
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Prostatic neuroendocrine cells, also known as endocrine-paracrine cells, are part of a larger regulatory cell population scattered throughout the whole organism, collectively known as diffuse neuroendocrine system or APUD cells. Neuroendocrine cells are present in all regions of the human prostate, most notably around the ducts, but also in the acinar epithelium and prostatic urothelium; there is a significant inter-individual variability. Two morphologic types have been described: the open type, extending slender apical processes to the ductal or acinar lumen, and the closed type cells, which lack lumenal protrusions but display dendrite-like processes that extend between adjacent epithelial cells. Neuroendocrine cells in the human prostate contain a diverse array of secretory products: serotonin (which is present in virtually all neuroendocrine prostatic cells), chromogranin A (CgA), synaptophysin and neuron-specific enolase (NSE) (three proteins that are used as markers for neuroendocrine cells) calcitonin and other peptides of the calcitonin family (calcitonin gene-related peptide (CGRP) and katacalcin, which colocalize to the calcitonin-containing cells), bombesin/gastrin-releasing peptide (GRP), thyroid stimulating hormone-like peptide, parathyroid hormone-related protein (PTHrP), alpha-human chorionic gonadotropin (hCG), somatostatin, cholecystokinin, vasoactive intestinal peptide (VIP), neuropeptide Y, vascular endothelial growth factor (VEGF), and adrenomedullin.
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