diurnal rhythm

• 概日周期、日周リズム

関

circadian rhythm、diurnal cycle

WordNet

1. of or belonging to or active during the day; "diurnal animals are active during the day"; "diurnal flowers are open during the day and closed at night"; "diurnal and nocturnal offices"
2. having a daily cycle or occurring every day; "diurnal rotation of the heavens"
3. recurring at regular intervals (同)regular recurrence
4. the basic rhythmic unit in a piece of music; "the piece has a fast rhythm"; "the conductor set the beat" (同)beat, musical rhythm
5. the arrangement of spoken words alternating stressed and unstressed elements; "the rhythm of Frosts poetry" (同)speech rhythm

PrepTutorEJDIC

1. 昼間の,日中の / 毎日起こる,日ごとの / (花が)昼咲きの,(鳥・昆虫などが)昼行性の
2. 〈U〉『律動,リズム』;韻律 / 〈C〉(特定の)リズム

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2016/06/14 04:14:55」(JST)

wiki en

[Wiki en表示]

"Sleep cycle" redirects here. For the album by Animal Collective member Deakin, see Sleep Cycle (album).

"Circadian" redirects here. For the album by the rock band 5th Projekt, see Circadian (album).

For the 2005 film, see Circadian Rhythm (film).

Some features of the human circadian (24-hour) biological clock

A circadian rhythm /sɜːrˈkeɪdiən/ is any biological process that displays an endogenous, entrainable oscillation of about 24 hours. These 24-hour rhythms are driven by a circadian clock, and they have been widely observed in plants, animals, fungi, and cyanobacteria.

The term circadian comes from the Latin circa, meaning "around" (or "approximately"), and diēm, meaning "day". The formal study of biological temporal rhythms, such as daily, tidal, weekly, seasonal, and annual rhythms, is called chronobiology. Processes with 24-hour oscillations are more generally called diurnal rhythms; strictly speaking, they should not be called circadian rhythms unless their endogenous nature is confirmed.

Although circadian rhythms are endogenous ("built-in", self-sustained), they are adjusted (entrained) to the local environment by external cues called zeitgebers (from German, "time giver"), which include light, temperature and redox cycles.

History

The earliest recorded account of a circadian process dates from the 4th century B.C.E., when Androsthenes, a ship captain serving under Alexander the Great, described diurnal leaf movements of the tamarind tree. The observation of a circadian or diurnal process in humans is mentioned in Chinese medical texts dated to around the 13th century, including the Noon and Midnight Manual and the Mnemonic Rhyme to Aid in the Selection of Acu-points According to the Diurnal Cycle, the Day of the Month and the Season of the Year.

The first recorded observation of an endogenous circadian oscillation was by the French scientist Jean-Jacques d'Ortous de Mairan in 1729. He noted that 24-hour patterns in the movement of the leaves of the plant Mimosa pudica continued even when the plants were kept in constant darkness, in the first experiment to attempt to distinguish an endogenous clock from responses to daily stimuli.

In 1896, Patrick and Gilbert observed that during a prolonged period of sleep deprivation, sleepiness increases and decreases with a period of approximately 24 hours. In 1918, J.S. Szymanski showed that animals are capable of maintaining 24-hour activity patterns in the absence of external cues such as light and changes in temperature. In the early 20th century, circadian rhythms were noticed in the rhythmic feeding times of bees. Extensive experiments were done by Auguste Forel, Ingeborg Beling, and Oskar Wahl to see whether this rhythm was due to an endogenous clock. Ron Konopka and Seymour Benzer isolated the first clock mutant in Drosophila in the early 1970s and mapped the "period" gene, the first discovered genetic determinant of behavioral rhythmicity. Joseph Takahashi discovered the first mammalian circadian clock mutation (clockΔ19) using mice in 1994. However, recent studies show that deletion of clock does not lead to a behavioral phenotype (the animals still have normal circadian rhythms), which questions its importance in rhythm generation.

The term circadian was coined by Franz Halberg in the 1950s.

Criteria

To be called circadian, a biological rhythm must meet these three general criteria:

1. The rhythm has an endogenous free-running period that lasts approximately 24 hours. The rhythm persists in constant conditions, (i.e., constant darkness) with a period of about 24 hours. The period of the rhythm in constant conditions is called the free-running period and is denoted by the Greek letter τ (tau). The rationale for this criterion is to distinguish circadian rhythms from simple responses to daily external cues. A rhythm cannot be said to be endogenous unless it has been tested and persists in conditions without external periodic input. In diurnal animals (active during daylight hours), in general τ is slightly greater than 24 hours, whereas, in nocturnal animals (active at night), in general τ is shorter than 24 hours.
2. The rhythms are entrainable. 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.
3. The rhythms exhibit temperature compensation. In other words, they maintain circadian periodicity over a range of physiological temperatures. Many organisms live at a broad range of temperatures, and differences in thermal energy will affect the kinetics of all molecular processes in their cell(s). In order to keep track of time, the organism's circadian clock must maintain roughly a 24-hour periodicity despite the changing kinetics, a property known as temperature compensation. The Q10 Temperature Coefficient is a measure of this compensating effect. If the Q10 coefficient remains approximately 1 as temperature increases, the rhythm is considered to be temperature-compensated.

Origin

Circadian rhythms allow organisms to anticipate and prepare for precise and regular environmental changes. They thus enable organisms to best capitalize on environmental resources (e.g. light and food) compared to those that cannot predict such availability. It has therefore been suggested that circadian rhythms put organisms at a selective advantage in evolutionary terms. However, rhythmicity appears to be as important in regulating and coordinating internal metabolic processes, as in coordinating with the environment. This is suggested by the maintenance (heritability) of circadian rhythms in fruit flies after several hundred generations in constant laboratory conditions, as well as in creatures in constant darkness in the wild, and by the experimental elimination of behavioral, but not physiological, circadian rhythms in quail.

What drove circadian rhythms to evolve has been an enigmatic question. Previous hypotheses emphasized that photosensitive proteins and circadian rhythms may have originated together in the earliest cells, with the purpose of protecting replicating DNA from high levels of damaging ultraviolet radiation during the daytime. As a result, replication was relegated to the dark. However, evidence for this is lacking, since the simplest organisms with a circadian rhythm, the cyanobacteria, do the opposite of this - they divide more in the daytime. Recent studies instead highlight the importance of co-evolution of redox proteins with circadian oscillators in all three kingdoms of life following the Great Oxidation Event approximately 2.3 billion years ago. The current view is that circadian changes in environmental oxygen levels and the production of reactive oxygen species (ROS) in the presence of daylight are likely to have driven a need to evolve circadian rhythms to preempt, and therefore counteract, damaging redox reactions on a daily basis.

The simplest known circadian clock is that of the prokaryotic cyanobacteria. Recent research has demonstrated that the circadian clock of Synechococcus elongatus can be reconstituted in vitro with just the three proteins (KaiA, KaiB, KaiC) of their central oscillator. This clock has been shown to sustain a 22-hour rhythm over several days upon the addition of ATP. Previous explanations of the prokaryotic circadian timekeeper were dependent upon a DNA transcription/translation feedback mechanism.

A defect in the human homologue of the Drosophila "period" gene was identified as a cause of the sleep disorder FASPS (Familial advanced sleep phase syndrome), underscoring the conserved nature of the molecular circadian clock through evolution. Many more genetic components of the biological clock are now known. Their interactions result in an interlocked feedback loop of gene products resulting in periodic fluctuations that the cells of the body interpret as a specific time of the day.

It is now known that the molecular circadian clock can function within a single cell; i.e., it is cell-autonomous. This was shown by Gene Block in isolated mollusk BRNs. At the same time, different cells may communicate with each other resulting in a synchronised output of electrical signaling. These may interface with endocrine glands of the brain to result in periodic release of hormones. The receptors for these hormones may be located far across the body and synchronise the peripheral clocks of various organs. Thus, the information of the time of the day as relayed by the eyes travels to the clock in the brain, and, through that, clocks in the rest of the body may be synchronised. This is how the timing of, for example, sleep/wake, body temperature, thirst, and appetite are coordinately controlled by the biological clock.

Importance in animals

Circadian rhythmicity is present in the sleeping and feeding patterns of animals, including human beings. There are also clear patterns of core body temperature, brain wave activity, hormone production, cell regeneration, and other biological activities. In addition, photoperiodism, the physiological reaction of organisms to the length of day or night, is vital to both plants and animals, and the circadian system plays a role in the measurement and interpretation of day length.

Timely prediction of seasonal periods of weather conditions, food availability, or predator activity is crucial for survival of many species. Although not the only parameter, the changing length of the photoperiod ('daylength') is the most predictive environmental cue for the seasonal timing of physiology and behavior, most notably for timing of migration, hibernation, and reproduction.

Impact of circadian disruption

Mutations or deletions of clock gene in mice have demonstrated the importance of body clocks to ensure the proper timing of cellular/metabolic events; clock-mutant mice are hyperphagic and obese, and have altered glucose metabolism. In mice, deletion of the Rev-ErbA alpha clock gene facilitates diet-induced obesity and changes the balance between glucose and lipid utilization predisposing to diabetes. However, it is not clear whether there is a strong association between clock gene polymorphisms in humans and the susceptibility to develop the metabolic syndrome.

Impact of light–dark cycle

The rhythm is linked to the light–dark cycle. Animals, including humans, kept in total darkness for extended periods eventually function with a free-running rhythm. Their sleep cycle is pushed back or forward each "day", depending on whether their "day", their endogenous period, is shorter or longer than 24 hours. The environmental cues that reset the rhythms each day are called zeitgebers (from the German, "time-givers"). Totally blind subterranean mammals (e.g., blind mole rat Spalax sp.) are able to maintain their endogenous clocks in the apparent absence of external stimuli. Although they lack image-forming eyes, their photoreceptors (which detect light) are still functional; they do surface periodically as well.

Free-running organisms that normally have one or two consolidated sleep episodes will still have them when in an environment shielded from external cues, but the rhythm is, of course, not entrained to the 24-hour light–dark cycle in nature. The sleep–wake rhythm may, in these circumstances, become out of phase with other circadian or ultradian rhythms such as metabolic, hormonal, CNS electrical, or neurotransmitter rhythms.

Recent research has influenced the design of spacecraft environments, as systems that mimic the light–dark cycle have been found to be highly beneficial to astronauts.

Arctic animals

Norwegian researchers at the University of Tromsø have shown that some Arctic animals (ptarmigan, reindeer) show circadian rhythms only in the parts of the year that have daily sunrises and sunsets. In one study of reindeer, animals at 70 degrees North showed circadian rhythms in the autumn, winter and spring, but not in the summer. Reindeer on Svalbard at 78 degrees North showed such rhythms only in autumn and spring. The researchers suspect that other Arctic animals as well may not show circadian rhythms in the constant light of summer and the constant dark of winter.

A 2006 study in northern Alaska found that day-living ground squirrels and nocturnal porcupines strictly maintain their circadian rhythms through 82 days and nights of sunshine. The researchers speculate that these two rodents notice that the apparent distance between the sun and the horizon is shortest once a day, and, thus, a sufficient signal to entrain (adjust) by.

Butterfly migration

The navigation of the fall migration of the Eastern North American monarch butterfly (Danaus plexippus) to their overwintering grounds in central Mexico uses a time-compensated sun compass that depends upon a circadian clock in their antennae.

In plants

Illustration of the morning (yellow) and evening (gray) circadian clock loops in Arabidopsis, entrainable through light. Transcriptional regulation is shown through black lines and protein complexes are denoted by dashed black lines. Post-translational regulation is shown by dashed red lines. Light sensitive elements are denoted with lightning bolts and yellow circles.

Sleeping tree by day and night

Plant circadian rhythms tell the plant what season it is and when to flower for the best chance of attracting pollinators. Behaviors showing rhythms include leaf movement, growth, germination, stomatal/gas exchange, enzyme activity, photosynthetic activity, and fragrance emission, among others. Circadian rhythms occur as a plant entrains to synchronize with the light cycle of its surrounding environment. These rhythms are endogenously generated and self-sustaining and are relatively constant over a range of ambient temperatures. Important features include two interacting transcription-translation feedback loops: proteins containing PAS domains, which facilitate protein-protein interactions; and several photoreceptors that fine-tune the clock to different light conditions. Anticipation of changes in the environment allows appropriate changes in a plant's physiological state, conferring an adaptive advantage. A better understanding of plant circadian rhythms has applications in agriculture, such as helping farmers stagger crop harvests to extend crop availability and securing against massive losses due to weather.

Light is the signal by which plants synchronize their internal clocks to their environment and is sensed by a wide variety of photoreceptors. Red and blue light are absorbed through several phytochromes and cryptochromes. One phytochrome, phyA, is the main phytochrome in seedlings grown in the dark but rapidly degrades in light to produce Cry1. Phytochromes B–E are more stable with phyB, the main phytochrome in seedlings grown in the light. The cryptochrome (cry) gene is also a light-sensitive component of the circadian clock and is thought to be involved both as a photoreceptor and as part of the clock's endogenous pacemaker mechanism. Cryptochromes 1–2 (involved in blue–UVA) help to maintain the period length in the clock through a whole range of light conditions.

The central oscillator generates a self-sustaining rhythm and is driven by two interacting feedback loops that are active at different times of day. The morning loop consists of CCA1 (Circadian and Clock-Associated 1) and LHY (Late Elongated Hypocotyl), which encode closely related MYB transcription factors that regulate circadian rhythms in Arabidopsis, as well as PRR 7 and 9 (Pseudo-Response Regulators.) The evening loop consists of GI (Gigantea) and ELF4, both involved in regulation of flowering time genes. When CCA1 and LHY are overexpressed (under constant light or dark conditions), plants become arrhythmic, and mRNA signals reduce, contributing to a negative feedback loop. Gene expression of CCA1 and LHY oscillates and peaks in the early morning, whereas TOC1 gene expression oscillates and peaks in the early evening. While it was previously hypothesised that these three genes model a negative feedback loop in which over-expressed CCA1 and LHY repress TOC1 and over-expressed TOC1 is a positive regulator of CCA1 and LHY, it was shown in 2012 by Andrew Millar and others that TOC1 in fact serves as a repressor not only of CCA1, LHY, and PRR7 and 9 in the morning loop but also of GI and ELF4 in the evening loop. This finding and further computational modeling of TOC1 gene functions and interactions suggest a reframing of the plant circadian clock as a triple negative-component repressilator model rather than the positive/negative-element feedback loop characterizing the clock in mammals.

Biological clock in mammals

A variation of an eskinogram illustrating the influence of light and darkness on circadian rhythms and related physiology and behaviour through the suprachiasmatic nucleus in humans.

The primary circadian clock in mammals is located in the suprachiasmatic nucleus (or nuclei) (SCN), a pair of distinct groups of cells located in the hypothalamus. Destruction of the SCN results in the complete absence of a regular sleep–wake rhythm. The SCN receives information about illumination through the eyes. The retina of the eye contains "classical" photoreceptors ("rods" and "cones"), which are used for conventional vision. But the retina also contains specialized ganglion cells that are directly photosensitive, and project directly to the SCN, where they help in the entrainment (synchronization) of this master circadian clock.

These cells contain the photopigment melanopsin and their signals follow a pathway called the retinohypothalamic tract, leading to the SCN. If cells from the SCN are removed and cultured, they maintain their own rhythm in the absence of external cues.

The SCN takes the information on the lengths of the day and night from the retina, interprets it, and passes it on to the pineal gland, a tiny structure shaped like a pine cone and located on the epithalamus. In response, the pineal secretes the hormone melatonin. Secretion of melatonin peaks at night and ebbs during the day and its presence provides information about night-length.

Several studies have indicated that pineal melatonin feeds back on SCN rhythmicity to modulate circadian patterns of activity and other processes. However, the nature and system-level significance of this feedback are unknown.

The circadian rhythms of humans can be entrained to slightly shorter and longer periods than the Earth's 24 hours. Researchers at Harvard have shown that human subjects can at least be entrained to a 23.5-hour cycle and a 24.65-hour cycle (the latter being the natural solar day-night cycle on the planet Mars).

Humans

Early research into circadian rhythms suggested that most people preferred a day closer to 25 hours when isolated from external stimuli like daylight and timekeeping. However, this research was faulty because it failed to shield the participants from artificial light. Although subjects were shielded from time cues (like clocks) and daylight, the researchers were not aware of the phase-delaying effects of indoor electric lights. The subjects were allowed to turn on light when they were awake and to turn it off when they wanted to sleep. Electric light in the evening delayed their circadian phase. A more stringent study conducted in 1999 by Harvard University estimated the natural human rhythm to be closer to 24 hours, 11 minutes: much closer to the solar day but still not perfectly in sync.

Biological markers and effects

The classic phase markers for measuring the timing of a mammal's circadian rhythm are:

• melatonin secretion by the pineal gland,
• core body temperature minimum, and
• plasma level of cortisol.

For temperature studies, subjects must remain awake but calm and semi-reclined in near darkness while their rectal temperatures are taken continuously. Though variation is great among normal chronotypes, the average human adult's temperature reaches its minimum at about 05:00 (5 a.m.), about two hours before habitual wake time. Baehr et al. found that, in young adults, the daily body temperature minimum occurred at about 04:00 (4 a.m.) for morning types but at about 06:00 (6 a.m.) for evening types. This minimum occurred at approximately the middle of the eight-hour sleep period for morning types, but closer to waking in evening types.

Melatonin is absent from the system or undetectably low during daytime. Its onset in dim light, dim-light melatonin onset (DLMO), at roughly 21:00 (9 p.m.) can be measured in the blood or the saliva. Its major metabolite can also be measured in morning urine. Both DLMO and the midpoint (in time) of the presence of the hormone in the blood or saliva have been used as circadian markers. However, newer research indicates that the melatonin offset may be the more reliable marker. Benloucif et al. found that melatonin phase markers were more stable and more highly correlated with the timing of sleep than the core temperature minimum. They found that both sleep offset and melatonin offset are more strongly correlated with phase markers than the onset of sleep. In addition, the declining phase of the melatonin levels is more reliable and stable than the termination of melatonin synthesis.

Other physiological changes that occur according to a circadian rhythm include heart rate and many cellular processes "including oxidative stress, cell metabolism, immune and inflammatory responses, epigenetic modification, hypoxia/hyperoxia response pathways, endoplasmic reticular stress, autophagy, and regulation of the stem cell environment. In a study of young men, it was found that the heart rate reaches its lowest average rate during sleep, and its highest average rate shortly after waking.

In contradiction to previous studies, it has been found that there is no effect of body temperature on performance on psychological tests. This is likely due to evolutionary pressures for higher cognitive function compared to the other areas of function examined in previous studies.

Outside the "master clock"

More-or-less independent circadian rhythms are found in many organs and cells in the body outside the suprachiasmatic nuclei (SCN), the "master clock". These clocks, called peripheral oscillators, are found in the adrenal gland, oesophagus, lungs, liver, pancreas, spleen, thymus, and skin. Though oscillators in the skin respond to light, a systemic influence has not been proven. There is also some evidence that the olfactory bulb and prostate may experience oscillations when cultured, suggesting that these structures may also be weak oscillators.

Furthermore, liver cells, for example, appear to respond to feeding rather than to light. Cells from many parts of the body appear to have free-running rhythms.

Light and the biological clock

Further information: Light effects on circadian rhythm

Light resets the biological clock in accordance with the phase response curve (PRC). Depending on the timing, light can advance or delay the circadian rhythm. Both the PRC and the required illuminance vary from species to species and lower light levels are required to reset the clocks in nocturnal rodents than in humans.

Enforced longer cycles

Studies by Nathaniel Kleitman in 1938 and by Derk-Jan Dijk and Charles Czeisler in the 1990s put human subjects on enforced 28-hour sleep–wake cycles, in constant dim light and with other time cues suppressed, for over a month. Because normal people cannot entrain to a 28-hour day in dim light if at all, this is referred to as a forced desynchrony protocol. Sleep and wake episodes are uncoupled from the endogenous circadian period of about 24.18 hours and researchers are allowed to assess the effects of circadian phase on aspects of sleep and wakefulness including sleep latency and other functions.

Human health

A short nap during the day does not affect circadian rhythms.

Timing of medical treatment in coordination with the body clock may significantly increase efficacy and reduce drug toxicity or adverse reactions.

A number of studies have concluded that a short period of sleep during the day, a power-nap, does not have any measurable effect on normal circadian rhythms but can decrease stress and improve productivity.

Health problems can result from a disturbance to the circadian rhythm. Circadian rhythms also play a part in the reticular activating system, which is crucial for maintaining a state of consciousness. A reversal in the sleep–wake cycle may be a sign or complication of uremia, azotemia or acute renal failure.

Studies have also shown that light has a direct effect on human health because of the way it influences the circadian rhythms.

Indoor lighting

Lighting requirements for circadian regulation are not simply the same as those for vision; planning of indoor lighting in offices and institutions is beginning to take this into account. Animal studies on the effects of light in laboratory conditions have until recently considered light intensity (irradiance) but not color which can be shown to "act as an essential regulator of biological timing in more natural settings".

Obesity and diabetes

Obesity and diabetes are associated with lifestyle and genetic factors. Among those factors, disruption of the circadian clockwork and/or misalignment of the circadian timing system with the external environment (e.g., light-dark cycle) might play a role in the development of metabolic disorders.

Shift-work or chronic jet-lag have profound consequences on circadian and metabolic events in the body. Animals that are forced to eat during their resting period show increased body mass and altered expression of clock and metabolic genes. In humans, shift-work that favors irregular eating times is associated with altered insulin sensitivity and higher body mass. Shift-work also leads to increased metabolic risks for cardio-metabolic syndrome, hypertension, inflammation.

Airline pilots

Due to the work nature of airline pilots, who often cross several timezones and regions of sunlight and darkness in one day, and spend many hours awake both day and night, they are often unable to maintain sleep patterns that correspond to the natural human circadian rhythm; this situation can easily lead to fatigue. The NTSB cites this as contributing to many accidents and has conducted several research studies in order to find methods of combating fatigue in pilots.

Disruption

Further information: Circadian rhythm sleep disorder

Disruption to rhythms usually has a negative effect. Many travellers have experienced the condition known as jet lag, with its associated symptoms of fatigue, disorientation, and insomnia.

A number of other disorders, for example bipolar disorder and some sleep disorders such as delayed sleep phase disorder (DSPD), are associated with irregular or pathological functioning of circadian rhythms.

Disruption to rhythms in the longer term is believed to have significant adverse health consequences on peripheral organs outside the brain, in particular in the development or exacerbation of cardiovascular disease. Blue LED lighting suppresses melatonin production five times more than the orange-yellow high-pressure sodium (HPS) light; a metal halide lamp, which is white light, suppresses melatonin at a rate more than three times greater than HPS. Depression symptoms from long term nighttime light exposure can be undone by returning to a normal cycle.

Effect of drugs

Studies conducted on both animals and humans show major bidirectional relationships between the circadian system and abusive drugs. It is indicated that these abusive drugs affect the central circadian pacemaker. Individuals suffering from substance abuse display disrupted rhythms. These disrupted rhythms can increase the risk for substance abuse and relapse. It is possible that genetic and/or environmental disturbances to the normal sleep and wake cycle can increase the susceptibility to addiction.

It is difficult to determine if a disturbance in the circadian rhythm is at fault for an increase in prevalence for substance abuse or if other environmental factors such as stress are to blame. Changes to the circadian rhythm and sleep occur once an individual begins abusing drugs and alcohol. Once an individual chooses to stop using drugs and alcohol, the circadian rhythm continues to be disrupted.

The stabilization of sleep and the circadian rhythm might possibly help to reduce the vulnerability to addiction and reduce the chances of relapse.

Circadian rhythms and clock genes expressed in brain regions outside the suprachiasmatic nucleus may significantly influence the effects produced by drugs such as cocaine. Moreover, genetic manipulations of clock genes profoundly affect cocaine's actions.

See also

• Actigraphy (also known as Actimetry)
• ARNTL
• ARNTL2
• Bacterial circadian rhythms
• Circadian rhythm sleep disorders, such as
  • Advanced sleep phase disorder
  • Delayed sleep phase disorder
  • Non-24-hour sleep-wake disorder
• Circasemidian rhythm
• Circaseptan, 7-day biological cycle
• Cryptochrome
• CRY1 and CRY2: the cryptochrome family genes

• Diurnal cycle
• Light effects on circadian rhythm
• Light in school buildings
• PER1, PER2, and PER3: the period family genes
• Photosensitive ganglion cell: part of the eye which is involved in regulating circadian rhythm.
• Polyphasic sleep
• Rev-ErbA alpha
• Segmented sleep
• Sleep architecture
• Stefania Follini

References

Further reading

• Aschoff, J. (ed.) (1965) Circadian Clocks. North Holland Press, Amsterdam
• Avivi, A.; Albrecht, U.; Oster, H.; Joel, A.; Beiles, A.; Nevo, E. (November 2001). "Biological clock in total darkness: the Clock/MOP3 circadian system of the blind subterranean mole rat". Proceedings of the National Academy of Sciences of the United States of America 98 (24): 13751–6. Bibcode:2001PNAS...9813751A. doi:10.1073/pnas.181484498. PMC 61113. PMID 11707566. 
• Avivi, A.; Oster, H.; Joel, A.; Beiles, A.; Albrecht, U.; Nevo, E. (September 2002). "Circadian genes in a blind subterranean mammal II: conservation and uniqueness of the three Period homologs in the blind subterranean mole rat, Spalax ehrenbergi superspecies". Proceedings of the National Academy of Sciences of the United States of America 99 (18): 11718–23. Bibcode:2002PNAS...9911718A. doi:10.1073/pnas.182423299. PMC 129335. PMID 12193657. 
• Li D, Ma S, Guo D, et al. (February 2016). "Environmental circadian disruption worsens neurologic impairment and inhibits hippocampal neurogenesis in adult rats after traumatic brain injury". Cell Mol Neurobiol. doi:10.1007/s10571-015-0295-2. PMID 26886755. 
• Ditty, J.L.; Williams, S.B.; Golden, S.S. (2003). "A cyanobacterial circadian timing mechanism". Annual Review of Genetics 37: 513–43. doi:10.1146/annurev.genet.37.110801.142716. PMID 14616072. 
• Dunlap, J.C.; Loros, J.; DeCoursey, P.J. (2003) Chronobiology: Biological Timekeeping. Sinauer, Sunderland
• Dvornyk, V.; Vinogradova, O.; Nevo, E. (March 2003). "Origin and evolution of circadian clock genes in prokaryotes". Proceedings of the National Academy of Sciences of the United States of America 100 (5): 2495–500. Bibcode:2003PNAS..100.2495D. doi:10.1073/pnas.0130099100. PMC 151369. PMID 12604787. 
• Koukkari, W.L.; Sothern, R.B. (2006) Introducing Biological Rhythms. Springer, New York
• Martino, T.; Arab, S.; Straume, M.; Belsham, Denise D.; et al. (April 2004). "Day/night rhythms in gene expression of the normal murine heart". Journal of Molecular Medicine 82 (4): 256–64. doi:10.1007/s00109-003-0520-1. PMID 14985853. 
• Refinetti, R. (2006) Circadian Physiology, 2nd ed. CRC Press, Boca Raton
• Takahashi, J.S.; Zatz, M. (September 1982). "Regulation of circadian rhythmicity". Science 217 (4565): 1104–11. Bibcode:1982Sci...217.1104T. doi:10.1126/science.6287576. PMID 6287576. 
• Tomita, J.; Nakajima, M.; Kondo, T.; Iwasaki, H. (January 2005). "No transcription-translation feedback in circadian rhythm of KaiC phosphorylation". Science 307 (5707): 251–4. Bibcode:2005Sci...307..251T. doi:10.1126/science.1102540. PMID 15550625. 
• Moore-Ede, Martin C.; Sulzman, Frank M.; Fuller, Charles A. (1982). The Clocks that Time Us: Physiology of the Circadian Timing System. Cambridge, Massachusetts: Harvard University Press. ISBN 0-674-13581-4. 

External links

• Circadian rhythm at DMOZ

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

• 1. クッシング症候群の原因および病態生理 causes and pathophysiology of cushings syndrome
• 2. 副腎皮質機能の臨床検査の基本原則 basic principles in the laboratory evaluation of adrenocortical function
• 3. 妊娠中のクッシング症候群 cushings syndrome in pregnancy
• 4. レプチンの生理学 physiology of leptin
• 5. 成人における副腎不全の治療 treatment of adrenal insufficiency in adults

English Journal

• Perinatal administration of aromatase inhibitors in rodents as animal models of human male homosexuality: similarities and differences.

• Olvera-Hernández S1, Fernández-Guasti A.
• Advances in neurobiology.Adv Neurobiol.2015;10:381-406. doi: 10.1007/978-1-4939-1372-5_18.
• In this chapter we briefly review the evidence supporting the existence of biological influences on sexual orientation. We focus on basic research studies that have affected the estrogen synthesis during the critical periods of brain sexual differentiation in male rat offspring with the use of aroma
• PMID 25287550

• Circadian use of glucocorticoids in rheumatoid arthritis.

• Cutolo M1, Sulli A, Pincus T.
• Neuroimmunomodulation.Neuroimmunomodulation.2015;22(1-2):33-9. doi: 10.1159/000362733. Epub 2014 Sep 12.
• A clear temporal relationship exists in rheumatoid arthritis (RA) patients between increased nocturnal levels of pro-inflammatory cytokines, such as TNF-α and interleukin (IL)-6, pro-inflammatory hormones (i.e. melatonin, prolactin) and insufficient night production of the anti-inflammatory corti
• PMID 25227591

• Role of endogenous ACTH on circadian aldosterone rhythm in patients with primary aldosteronism.

• Sonoyama T1, Sone M2, Tamura N1, Honda K1, Taura D1, Kojima K1, Fukuda Y1, Kanamoto N1, Miura M1, Yasoda A1, Arai H1, Itoh H1, Nakao K1.
• Endocrine connections.Endocr Connect.2014 Dec;3(4):173-9. doi: 10.1530/EC-14-0086.
• We recently reported that stimulation with high-dose ACTH caused different responses in terms of aldosterone secretion in aldosterone-producing adenomas (APAs) and idiopathic hyperaldosteronism (IHA) in patients with primary aldosteronism (PA). However, the role of endogenous ACTH in aldosterone sec
• PMID 25239966

Japanese Journal

• 時間栄養学

• 内分泌・糖尿病・代謝内科 = Endocrinology, diabetology & metabolism 41(1), 70-77, 2015-07
• NAID 40020553995

• 持久的運動時の唾液中α-アミラーゼ活性値の変動要因

• 鳴門教育大学研究紀要 30, 485-493, 2015-03-13
• NAID 110009895537

• ハダムシNeobenedenia girellaeの産卵とふ化の日周リズム

• 魚病研究 50(1), 23-28, 2015-03
• NAID 40020405591

Related Pictures

---

★リンクテーブル★

リンク元	「日周リズム」「diurnal cycle」
関連記事	「diurnal」「rhythm」

「日周リズム」

　　[★]

英

circadian rhythm、diurnal rhythm

関

概日周期、サーカディアンリズム、日内変動、日周性リズム、概日リズム

「diurnal cycle」

　　[★]

• 日内周期、概日周期

関

circadian rhythm、diurnal rhythm

「diurnal」

　　[★]

• adj.

• 昼間の、日中の(⇔nocturnal)
• 日ごとの(daily)。1日昼夜の、日周的な

　 　 　

「rhythm」

　　[★]

• n.

• リズム