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  • Chronobiology
  • Recent studies in clinical chronobiology have revealed that a chronic sleep phase delay (delayd sleep phase syndrome (DSPS)), or a chronic free-running sleep-wake rhythm (non-24 hour sleep-wake syndrome (non-24)) was also observed in sighted subjects living under a normal light-dark cycle. (nii.ac.jp)
  • Stampi has written about his research in his book Why We Nap: Evolution, Chronobiology, and Functions of Polyphasic and Ultrashort Sleep (1992). (wikipedia.org)
  • endogenous
  • strictly speaking, they should not be called circadian rhythms unless their endogenous nature is confirmed. (wikipedia.org)
  • The first recorded observation of an endogenous circadian oscillation was by the French scientist Jean-Jacques d'Ortous de Mairan in 1729. (wikipedia.org)
  • citation needed] Neurons in the dorsomedial SCN (dmSCN) are believed to have an endogenous 24-hour rhythm that can persist under constant darkness (in humans averaging about 24 hours 11 min). (wikipedia.org)
  • Mice
  • However, when melanopsin was knocked out in blind mice without rods and cones, they exhibited "complete loss of photoentrainment of the circadian oscillator, pupillary light responses, photic suppression of arylalkylamine-N-acetyltransferase transcript, and acute suppression of locomotor activity by light. (wikipedia.org)
  • These mice had a circadian period almost 2 hours shorter than wild-type animals. (wikipedia.org)
  • behaviors
  • citation needed] Information about the direct neuronal regulation of metabolic processes and circadian rhythm-controlled behaviors is not well known among either endothermic or ectothermic vertebrates, although extensive research has been done on the SCN in model animals such as the mammalian mouse and ectothermic reptiles, in particular, lizards. (wikipedia.org)
  • The behavioral differences between both classes of vertebrates, when compared to the respective structures and properties of the SCN and various other nuclei proximate to the hypothalamus, provide insight into how these behaviors are the consequence of differing circadian regulation. (wikipedia.org)
  • Ultimately, many neuroethological studies must be done to completely ascertain the direct and indirect roles of the SCN on circadian-regulated behaviors of vertebrates. (wikipedia.org)
  • Homeostatic
  • At the cellular level, we may be able to compensate for the inability to study living brain tissue through the study of homeostatic mechanisms in fibroblasts, pluripotent human cells, and mitochondria and determine how homeostasis is disturbed at the level of these peripheral tissues through exogenous stress. (ox.ac.uk)
  • Internal circadian indicators, along with successful reduction of homeostatic sleep need, typically bring about awakening and the end of the sleep episode. (wikipedia.org)
  • mood
  • Influencing circadian and sleep-wake regulation for prevention and intervention in mood and anxiety disorders: what makes a good homeostat? (ox.ac.uk)
  • In particular, it addresses the ways in which understanding of disturbed homeostasis may aid in creating classes of patients with mood and anxiety disorders based on such phenotypes. (ox.ac.uk)
  • CONCLUSIONS: Severe circadian sleep/wake disruptions exist despite stability in mood, mental state and newer antipsychotic treatment. (ox.ac.uk)
  • In addition to mood, learning and memory become impaired when the circadian system shifts due to light stimuli, which can be seen in studies modeling jet lag and shift work situations. (wikipedia.org)
  • SYNDROME
  • Study 2 : Our prior study indicated that melatonin treatment was effective in 50% of patients with delayd sleep phase syndrome or non-24-hour sleep-wake syndrome when it was administerd once 1-2 hours before the patient's desired bedtime (dose : 1-6 mg). (nii.ac.jp)
  • Morningness-eveningness questionnaire (MEQ) Munich ChronoType Questionnaire (MCTQ) Waking up early Night owl (person) Advanced sleep phase syndrome Circadian rhythm sleep disorder FASPS Horne JA, Östberg O (1976). (wikipedia.org)
  • Advanced sleep phase disorder (ASPD), also known as the advanced sleep-phase type (ASPT) of circadian rhythm sleep disorder or advanced sleep phase syndrome (ASPS), is a condition in which patients feel very sleepy and go to bed early in the evening (e.g. 6:00-8:00 p.m.) and wake up very early in the morning (e.g. around 3:00 a.m. (wikipedia.org)
  • As stated below, several genes have been discovered to have links with this syndrome and the body's circadian rhythms. (wikipedia.org)
  • Schizophrenia
  • We summarise recent clinical evidence that supports this hypothesis, including the observation that the treatment of SCRD leads to improvements in both the sleep quality and psychiatric symptoms of schizophrenia patients. (ox.ac.uk)
  • DSPD
  • As with delayed sleep phase disorder (DSPS or DSPD), in the absence of neurological damage due to trauma or stroke, cases almost never appear after the age of 30. (wikipedia.org)
  • People with DSPD (Delayed sleep phase disorder), more common than Non-24, do entrain to nature's 24 hours, but are unable to sleep and awaken at socially preferred times, sleeping instead, for example, from 4 a.m. to noon. (wikipedia.org)
  • These have been genetically linked by findings of polymorphism in genes in common between those apparently involved in ADHD and those involved in the circadian rhythm and a high proportion of DSPD among those with ADHD, however no specific or further cause-effect relationship has been proven. (wikipedia.org)
  • A chief difficulty of treating DSPD is in maintaining an earlier schedule after it has been established, as the patient's body has a strong tendency to reset the sleeping schedule to its intrinsic late times. (wikipedia.org)
  • People with DSPD may improve their quality of life by choosing careers that allow late sleeping times, rather than forcing themselves to follow a conventional 9-to-5 work schedule. (wikipedia.org)
  • In contrast, people with DSPD have difficulty falling asleep before their usual sleep time, even if they are sleep-deprived. (wikipedia.org)
  • Non -DSPD people who do not adjust well to working a night shift have similar symptoms (diagnosed as shift-work sleep disorder ). (wikipedia.org)
  • occur
  • The period of sleep during which eyes move rapidly behind closed eyelids and when dreams most commonly occur. (scienceclarified.com)
  • The most pronounced physiological changes in sleep occur in the brain. (wikipedia.org)
  • Occasional noncircadian days may occur (i.e., sleep is "skipped" for an entire day and night plus some portion of the following day), followed by a sleep period lasting 12 to 18 hours. (wikipedia.org)
  • behavioral
  • It is important to decide whether sleeping on the plane is in the best interest of the passenger," says Dr. Lisa Medalie, behavioral sleep medicine specialist at University of Chicago Medicine. (talkaboutsleep.com)
  • non-REM and REM sleep are so different that physiologists identify them as distinct behavioral states. (wikipedia.org)
  • Photoentrainment
  • However, in the absence of either rods and cones or melanopsin, melanopsin becomes necessary for photoentrainment of the circadian oscillator and for other photic responses. (wikipedia.org)
  • seasonal
  • Properties of natural or artificial light that may abnormally affect people include: Timing of light (upset of normal circadian rhythms, seasonal affective disorder, sleep disorders) Intensity of light (photophobia, sunburn, skin cancer) Wavelength of light (in lupus, urticaria) Rapid flickers in intensity of light may trigger or aggravate photosensitive epilepsy, epileptic seizure, or migraine headaches. (wikipedia.org)
  • Seasonal affective disorder creates a model in which decreased day length during autumn and winter increases depressive symptoms. (wikipedia.org)
  • Narcolepsy
  • In addition to falling asleep at unexpected times, people with narcolepsy may have loss of muscle control during emotional situations, hallucinations, temporary paralysis, and disrupted nighttime sleep. (nih.gov)
  • Narcolepsy tends to run in families with a history of sleep disorders, and it also occurs in some people who have experienced head trauma or injury. (nih.gov)
  • mammals
  • Polyphasic sleep is common in many animals, and is believed to be the ancestral sleep state for mammals, although simians are monophasic. (wikipedia.org)
  • known
  • Melatonin receptor 1B, also known as MTNR1B, is a protein that in humans is encoded by the MTNR1B gene. (wikipedia.org)
  • Ancient humans believed that the soul left the body during sleep, and the well-known prayer that includes the words, 'if I should die before I wake,' tells us something about the fear we may experience when we surrender to unconsciousness every night. (scienceclarified.com)
  • This adaptation to earlier sleep/wake times is known as "advancing the sleep phase. (wikipedia.org)
  • Exogenous melatonin administration in humans is known to exert both chronobiotic (phase shifting) and soporific effects. (cdc.gov)
  • Known sleep or circadian rhythm disorder, not caused by lowered blue light transmission by the lens. (knowcancer.com)
  • A well-known feature of sleep is the dream, an experience typically recounted in narrative form, which resembles waking life while in progress, but which usually can later be distinguished as fantasy. (wikipedia.org)
  • REM sleep (also known as paradoxical sleep), a smaller portion of total sleep time and the main occasion for dreams (or nightmares), is associated with desynchronized and fast brain waves, eye movements, loss of muscle tone, and suspension of homeostasis. (wikipedia.org)
  • significantly
  • They found that, in free-running conditions, the average duration of major nighttime sleep was significantly longer in young adults than in the other groups. (wikipedia.org)
  • Especially during non-REM sleep, the brain uses significantly less energy during sleep than it does in waking. (wikipedia.org)
  • These studies also show that blind patients who cannot entrain and lack melanopsin cells have a significantly greater risk of suffering from circadian rhythm sleep disorders. (wikipedia.org)
  • mechanisms
  • Here, we propose that the co-morbidity of these disorders stems from the involvement of common brain mechanisms. (ox.ac.uk)
  • From these perspectives, animal and/or human research is aimed at understanding the molecular, neurophysiological or neuronal mechanisms controlling the sleep-wake cycle and states. (sleepresearchsociety.org)
  • The diverse purposes and mechanisms of sleep are the subject of substantial ongoing research. (wikipedia.org)
  • shifts
  • In a previous study in our lab, young, healthy, subjects worked five consecutive simulated night shifts (23:00 to 07:00 h) and slept during the day (08:30 to 15:30 h). (cdc.gov)
  • affects
  • This change in work schedule affects the sleep cycle. (newsmax.com)
  • It affects both men and women equally and has been determined to have a strong genetic, link with 40-50% of sufferers having relatives with the disorder. (wikipedia.org)
  • time
  • At the end of the first cycle, each time a person reenters Stage I, he or she begins an interesting sleep stage called Rapid Eye Movement or REM sleep. (scienceclarified.com)
  • can sleep and wake up at the same time every day, if they want to. (wikipedia.org)
  • Due to the change in time zones, the person either goes to sleep early and wakes up early, or sleeps late and wakes up late. (newsmax.com)
  • Sleep log measurements of total sleep time (TST) and actigraphic measurements of sleep latency, TST, and three movement indices for the two groups were examined. (cdc.gov)
  • Affected people often report that while they do not get to sleep until the early morning, they do fall asleep around the same time every day. (wikipedia.org)
  • Circadian rhythms also tell plants when to flower, when the best time is for photosynthetic activity, and when to release fragrances. (reference.com)
  • Note: term describes rhythms with an about 24-h cycle length, whether they are frequency-synchronized with (acceptable) or are desynchronized or free-running from the local environmental time scale, with periods of slightly yet consistently different from 24-h. (wikipedia.org)
  • Some ask what time people do go to sleep and wake up-others ask what time people would prefer to. (wikipedia.org)
  • The term polyphasic sleep is also used by an online community that experiments with alternative sleeping schedules to achieve more time awake each day. (wikipedia.org)
  • One study found 3% awake time in the first ninety-minute sleep cycle, 8% in the second, 10% in the third, 12% in the fourth, and 13-14% in the fifth. (wikipedia.org)
  • For example, total time of sleep is maintained in rats with SCN damage, but the length and timing of sleep episodes becomes erratic. (wikipedia.org)
  • During the period between two hours after usual wake-up time and two hours before usual bedtime, light exposure has little or no effect on circadian phase (slight effects generally cancelling each other out). (wikipedia.org)