Light acts as a "zeitgeber," a natural cue to our bodies' circadian rhythms.
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It's called a zeitgeber, the strongest input to the awake phase of our rhythm.
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Sunlight is a natural zeitgeber, or environmental cue that resets the circadian clock, he said.
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The term "zeitgeber" (, literally "time giver", i.e., "synchronizer") was first used by Jürgen Aschoff, one of the founders of the field of chronobiology. His work demonstrated the existence of endogenous (internal) biological clocks, which synchronize biological rhythms. In addition, he found that certain exogenous (external) cues, which he called zeitgeber, influence the timing of these internal clocks.
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Light is the primary Zeitgeber for the synchronization of biological rhythms. 2\. Light triggers photoinductive responses during certain phases of the circadian cycle.
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The social zeitgeber hypothesis therefore proposes, that in bipolar disorder the fundamental circadian instability can be moderated by the stabilization of daily rhythms and zeitgeber. According to the hypothesis a disruption (e.g. life events) could trigger depressive, hypomanic or manic episodes. A regular daily rhythm on the other hand can have a positive effect and lead to a normalization of the circadian system.
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A zeitgeber is any external or environmental cue that entrains or synchronizes an organism's biological rhythms to the Earth's 24-hour light/dark cycle and 12-month cycle.
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It has been suggested that, like the 24-hour circadian rhythm, the body also has a yearly "circannual" biological rhythm. Vaiserman et al. have suggested that the climatic conditions at birth act as a zeitgeber that triggers internal stress and increases the chance of death.
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23 Apr. 2013. Beling’s research was unable to conclusively show whether bees have some kind of internal biological clock that is controlling this behavior or if there is some external cue acting as a Zeitgeber that she did not account for in her experiments.
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After over twenty years of tracking sleep-wake cycles, body temperature, urine output, and other physiological and behavioral outputs, Aschoff and his collaborator Rütger Wever concluded that humans have endogenous circadian oscillators. This discovery has become the foundation for our understanding of many medical problems such as aging, sleep disorders, and jet lag. In 1960, Aschoff coined the term Zeitgeber (from German for "time giver" or "synchronizer") to refer to external, environmental cues that synchronize an endogenous oscillator to the environmental cycle. To investigate the properties of natural endogenous oscillators, Aschoff exposed organisms to constant conditions without Zeitgeber cues (either constant light or constant darkness).
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Also in 2008, Speedy J started releasing music on his own record label, Electric Deluxe, as well as records by Terence Fixmer, Gary Beck, Tommy Four Seven and others. In 2013, Speedy J and Luca Mortellaro released a collaborative album under the name Zeitgeber. It was released on Mortellaro's label Stroboscopic Artefacts.
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Smart lighting products which support color temperatures may be instructed to match a preset color temperature setting. As the presence of blue light is a major zeitgeber – a factor which influences the perception of time with regards to circadian rhythm – this feature is designed to encourage activity in the day and calmness in the morning and evening.
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Smart lighting products which support color temperatures may be instructed to match a preset color temperature setting. As the presence of blue light is a major zeitgeber – a factor which influences the perception of time with regards to circadian rhythm – this feature is designed to encourage activity in the day and calmness in the morning and evening.
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Zeitgebers (“time givers”) are environmental cues that synchronize biological rhythms to the 24-hour light/dark cycle. As the sun is a physical zeitgeber, social factors are considered social zeitgebers. These include personal relationships, social demands, or life tasks that entrain circadian rhythms. Disruptions in circadian rhythms can lead to somatic and cognitive symptoms, as seen in jet lag or during daylight saving time.
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Summary of pervasive effects of light The SCN of the hypothalamus contains an endogenous pacemaker that regulates circadian rhythms.Irwin, R. (2007). Calcium response to retinohypothalamic tract synaptic transmission in suprachiasmatic nucleus neurons., The zeitgeber found to have the most profound effect on the SCN is light, which is the form of stimulation of which conversion is needed for it to be processed by the brain.
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They wondered specifically about the regulation of period mRNA level fluctuations, and found that per mRNA levels were transcriptionally regulated. This was supported by the evidence that per precursor RNA cycles with the same phase as mature transcripts, and oscillate with respect to Zeitgeber Time (ZT). Other evidence for transcriptional regulation is that per gene promoter is sufficient to confer cycling to heterologous mRNA.
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A remix of one album track by "Dream Control" marks the start of Zeus' collaboration with former Tangerine Dream member Steve Schroyder. In August 2017 Dream Control's first album entitled "Zeitgeber" is released on Planetware Records. In October a special edited vinyl version of this album was released on U.S. label Medical Records. Currently Dream Control is working on a film project which should be released in early 2019.
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Much of Aschoff's later work involved tests on human subjects. He found that the absence of a light-dark cycle does not prevent humans from entrainment. Rather, knowing the time of day from social cues, such as regular meal times, is sufficient for entrainment. Aschoff also found that different circadian outputs such as body temperature and locomotor activity can be either internally synchronized or desynchronized depending on the strength of the Zeitgeber.
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Following up on his temperature studies, he found that a mammalian species can entrain to a temperature cycle, but that temperature is a weak Zeitgeber compared to a light-dark cycle. Aschoff described masking signals as inputs that circumvent the pacemaker but nevertheless lead to modulation of a circadian behavior that is also controlled by the pacemaker.Aschoff J: Masking of circadian rhythms by zeitgebers as opposed to entrainment. In: Trends in Chronobiology, ed.
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Roenneberg has also completed work on Neurospora crassa, determining the masking qualities of entrainment through a Frequency (gene)-null circadian oscillator. He observed in the period of spore production (conidia bands) the phenomenon of masking, an unexpected effect on circadian entrainment due to a particular zeitgeber (such as light or temperature). Masking has significant implications not only for future studies – which must attempt to demask affected data – but also in relation to entrainment in everyday life.
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The rhythm can be reset by exposure to external stimuli (such as light and heat), a process called entrainment. The external stimulus used to entrain a rhythm is called the Zeitgeber, or "time giver". Travel across time zones illustrates the ability of the human biological clock to adjust to the local time; a person will usually experience jet lag before entrainment of their circadian clock has brought it into sync with local time. # The rhythms exhibit temperature compensation.
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Since the internal clock sets itself using zeitgebers, the loss or disruption of an individual's usual zeitgebers can be very disorienting. When an individual experiences significant changes in zeitgebers, such as being irregularly scheduled for the night shift, those changes can have a variety of negative effects. One example of this phenomenon is jetlag, in which traveling to another time zone causes desynchronization in sleep-wake cycles, appetite, and emotions. Such zeitgeber disruptions can also lead to decreased cognitive performance, negative mood, and in some cases, episodes of mental illness.
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Schibler and his colleagues have also studied mechanisms by which peripheral oscillators are synchronized within the body. In 2000, they conducted experiments on the effects of restricted feeding time on mice and observed that the phase of peripheral oscillators - but not that of the SCN – gradually adapted to imposed feeding-fasting rhythms within a week or two. These results showed that feeding time functions as a potent Zeitgeber for peripheral cells, but not for the SCN. Schibler and colleagues posited that the SCN can synchronize peripheral clocks simply by imposing rest- activity cycles, which in turn drive feeding-fasting cycles.
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Taken together, findings from studies on bereaved spouses indicate that when bereavement is associated with changes in social rhythms, depressive symptoms are likely to increase; however, if bereaved individuals are able to maintain social rhythms after the death of their spouse, increased depression is less likely. These findings suggest that social rhythm stability may not be entirely dependent on life events, but rather has some traitlike elements as well, since some individuals may be more likely to maintain social rhythms than others following the occurrence of a significant life event. Recent studies have also found a connection between the disruption of social rhythms and the triggering of manic episodes in bipolar disorder. Differentiating between zeitgeber disturbances that lead to depression and those that lead to manic episodes has proven difficult.
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