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Encyclopedia > Rapid eye movement
For other uses of the acronym REM, see: REM (disambiguation).

Rapid eye movement (REM) sleep is the normal stage of sleep characterized by rapid movements of the eyes. REM sleep is classified into two categories: tonic and phasic. [1] It was discovered by Nathaniel Kleitman and Eugene Aserinsky in the early 1950s. Their seminal article was published September 4, 1953 (Aserinsky E, Kleitman N. Regularly Occurring Periods of Eye Motility, and Concomitant Phenomena, during Sleep. Science 1953:118;273-274). Criteria for REM sleep include not only rapid eye movements, but also low muscle tone and a rapid, low voltage EEG -- these features are easily discernible in a polysomnogram, the sleep study typically done for patients with suspected sleep disorders. Image File history File links Emblem-important. ... REM may be an acronym for: Rapid eye movement, a phase of sleep Rosicrucian Egyptian Museum, a museum about ancient Egypt Röntgen equivalent in man, a unit used in the United States for measuring levels of exposure to radiation. ... For other uses, see Sleep (disambiguation). ... Eye movements are the voluntary or involuntary movements of the eye. ... Nathaniel Kleitman (1895 - 1999) was Professor Emeritus in Physiology at the University of Chicago. ... Eugene Aserinsky (1921 – 1998) was a graduate student at University of Chicago in 1953 when he discovered REM sleep. ... Polysomnogram (PSG) is a multi-channel (poly) recording (gram) during sleep (somno). A doctor may order a polysomnogram because the patient has a complaint such as daytime fatigue or sleepiness that may be from interrupted sleep. ...

Polysomnographic record of REM Sleep. EEG highlighted by red box. Eye movements highlighted by red line.
Polysomnographic record of REM Sleep. EEG highlighted by red box. Eye movements highlighted by red line.

REM sleep in adults typically occupies 20-25% of total sleep, lasting about 90-120 minutes. During a normal night of sleep, we usually experience about 4 or 5 periods of REM sleep; they are quite short at the beginning of the night and longer at the end. It is common to wake for a short time at the end of a REM phase. The relative amount of REM sleep varies considerably with age. A newborn baby spends more than 80% of total sleep time in REM (see also Active Sleep). During REM, the summed activity of the brain's neurons is quite similar to that during waking hours; for this reason, the phenomenon is often called paradoxical sleep. This means that there are no dominating brain waves during REM sleep. Image File history File links Download high resolution version (821x601, 999 KB) Summary This is a screenshot of a polysomnographic record representing Rapid Eye Movement Sleep. ... Image File history File links Download high resolution version (821x601, 999 KB) Summary This is a screenshot of a polysomnographic record representing Rapid Eye Movement Sleep. ... Polysomnographic record of REM Sleep . ... Electroencephalography is the neurophysiologic exploration of the electrical activity of the brain by the application of electrodes to the scalp. ... Active Sleep It has been well documented that Active Sleep (AS), otherwise known as rapid eye movement (REM) sleep, is the dominant state during early development in both altricial and precocial mammals (Corner et al. ... For other uses, see Brain (disambiguation). ... Drawing by Santiago Ramón y Cajal of neurons in the pigeon cerebellum. ...

REM sleep is so physiologically different [citation needed] from the other phases of sleep that the others are collectively referred to as non-REM sleep. Most of our vividly recalled dreams occur during REM sleep. This article or section does not adequately cite its references or sources. ...

Sleep article categories
  • Sleep Stages
  • Sleep disorders
  • Benign sleep phenomena
  • Other Sleep-related Topics
  • Nightwear

Links to specific articles can be found in the navigation box at the bottom of this article Image File history File links Size of this preview: 800 × 593 pixelsFull resolution (2024 × 1501 pixel, file size: 245 KB, MIME type: image/jpeg) File historyClick on a date/time to view the file as it appeared at that time. ...


Physiology of REM sleep

See also: Neurology of dreams

Physiologically, certain neurons in the brain stem, known as REM sleep-on cells (located in the pontine tegmentum), are particularly active during REM sleep, and are probably responsible for its occurrence. The release of certain neurotransmitters, the monoamines (norepinephrine, serotonin and histamine), is completely shut down during REM. This causes REM atonia, a state in which the motor neurons are not stimulated and thus the body's muscles don't move. Lack of such REM atonia causes REM Behavior Disorder; sufferers act out the movements occurring in their dreams. For other uses, see Dream (disambiguation). ... The brain stem is the lower part of the brain, adjoining and structurally continuous with the spinal cord. ... The pontine tegmentum is a part of the pons of the brain involved in the initiation of REM sleep. ... Chemical structure of D-aspartic acid, a common amino acid neurotransmitter. ... In biochemistry, monoamines are a group of organic compounds containing only one amino group. ... Norepinephrine (INN)(abbr. ... Serotonin (pronounced ) (5-hydroxytryptamine, or 5-HT) is a monoamine neurotransmitter synthesized in serotonergic neurons in the central nervous system (CNS) and enterochromaffin cells in the gastrointestinal tract of animals including humans. ... This article or section does not cite any references or sources. ... In vertebrates, the term motor neuron (or motoneuron) classically applies to neurons located in the central nervous system (CNS) which project their axons outside the CNS and directly or indirectly control muscles. ... A top-down view of skeletal muscle Muscle (from Latin musculus little mouse [1]) is contractile tissue of the body and is derived from the mesodermal layer of embryonic germ cells. ... Rapid eye movement behavior disorder or REM behavior disorder (RBD) is a sleep disorder in which sleep paralysis, which normally disables the voluntary muscles during REM sleep, fails to occur. ...

Heart rate and breathing rate are irregular during REM sleep, again similar to the waking hours. Body temperature is not well regulated during REM. Erections of the penis (Nocturnal Penile Tumescence or NPT) is an established accompaniment of REM sleep and is used diagnostically to determine if male erectile dysfunction is of organic or psychological origin. Clitoral enlargement, with accompanying vaginal blood flow and transudation (i.e. lubrication) is also present during REM. Heart rate is a term used to describe the frequency of the cardiac cycle. ... Breathing transports oxygen into the body and carbon dioxide out of the body. ... Erected penis This article discusses human physiological erection. ... The penis (plural penises, penes) is an external male sexual organ. ... Nocturnal penile tumescence or slang Morning wood is an erection that occurs spontaneously in the absence of any specific sexual stimulation, particularly in adolescent males. ... The clitoris (Greek ) is a sexual organ that is present in biologically female mammals. ...

The eye movements associated with REM are generated by the pontine nucleus with projections to the superior colliculus and are associated with PGO (pons, geniculate, occipital) waves. For other uses, see Pons (disambiguation). ... The superior colliculus is part of the brain that sits below the thalamus and surrounds the pineal gland in the mesencephalon of vertebrate brains. ...

REM sleep disorders

See also: Sleep disorder

REM sleep can occur within about 90 minutes, but in those with a sleep onset REM period, it may be as little as 15-25 minutes. This is considered a sign of narcolepsy.[2] Narcolepsy is a neurological condition most characterized by Excessive Daytime Sleepiness (EDS). ...

Theories about the function(s) of REM sleep

The function of REM sleep is not well understood; several theories have been advanced.

According to one theory, certain memories are consolidated during REM sleep. Numerous studies have suggested that REM sleep is important for consolidation of procedural and spatial memories. (Slow-wave sleep, part of non-REM sleep, appears to be important for declarative memories.) A recent study (Marshall, Helgadóttir, Mölle & Born, 2006) shows that artificial enhancement of the REM sleep improves the next-day recall of memorized pairs of words. However, in people who have no REM sleep (because of brain damage), memory functions are not measurably affected.[3] For other uses, see Memory (disambiguation). ... Polysomnogram demonstrating SWS. High amplitude EEG is highlighted in red. ...

Another theory suggests that monoamine shutdown is required so that the monoamine receptors in the brain can recover to regain full sensitivity. Indeed, if REM sleep is repeatedly interrupted, the person will "make up" for it with longer REM sleep at the next opportunity. Acute REM sleep deprivation can improve certain types of depression, and depression appears to be related to an imbalance of certain neurotransmitters. Most antidepressants selectively inhibit REM sleep due to their effects on monoamines. However, this effect decreases after long-term use. In biochemistry, monoamines are a group of organic compounds containing only one amino group. ... Clinical depression (also called major depressive disorder, or unipolar depression when compared to bipolar disorder) is a state of intense sadness, melancholia or despair that has advanced to the point of being disruptive to an individuals social functioning and/or activities of daily living. ... A recent form of antidepressant medication - Prozac Serotonin-norepinephrine reuptake inhibitor, Venlafaxine An antidepressant, in the most common usage, is a psychiatric medication taken to alleviate clinical depression or dysthymia (milder depression). ...

According to a third theory, known as the Ontogenetic Hypothesis of REM sleep, this sleep phase (also known as Active Sleep in neonates) is particularly important to the developing brain, possibly because it provides the neural stimulation that newborns need to form mature neural connections and for proper nervous system development (Marks et al. 1995). Studies investigating the effects of Active Sleep deprivation have shown that deprivation early in life can result in behavioral problems, permanent sleep disruption, decreased brain mass (Mirmiran et al. 1983), and result in an abnormal amount of neuronal cell death (Morrissey, Duntley & Anch, 2004). REM sleep is necessary for proper central nervous system development (Marks et al. 1995). Further supporting this theory is the fact that the amount of REM sleep decreases with age, as well as the data from other species (see below). Active Sleep It has been well documented that Active Sleep (AS), otherwise known as rapid eye movement (REM) sleep, is the dominant state during early development in both altricial and precocial mammals (Corner et al. ... A human infant The word Infant derives from the Latin in-fans, meaning unable to speak. ...

REM sleep in other animals

REM sleep occurs in all mammals and birds. It appears that the amount of REM sleep per night in a species is closely correlated with the developmental stage of newborns. The platypus for example, whose newborns are completely helpless and undeveloped, has 8 hours of REM sleep per night. Subclasses & Infraclasses Subclass †Allotheria* Subclass Prototheria Subclass Theria Infraclass †Trituberculata Infraclass Metatheria Infraclass Eutheria Mammals (class Mammalia) are warm-blooded, vertebrate animals characterized by the presence of sweat glands, including those that produce milk, and by the presence of: hair, three middle ear bones used in hearing, and a neocortex... For other meanings of bird, see bird (disambiguation). ... For other uses, see Platypus (disambiguation). ...


The phenomenon of REM sleep and its association with dreaming was discovered by Eugene Aserinsky and Nathaniel Kleitman with assistance from William C. Dement, a medical student at the time, in 1952 during their tenures at the University of Chicago. Eugene Aserinsky (1921 – 1998) was a graduate student at University of Chicago in 1953 when he discovered REM sleep. ... The University of Chicago is a private university located principally in the Hyde Park neighborhood of Chicago. ...

REM sleep suppression

Various drugs, including alcohol, benzodiazepines, and antidepressants are known to suppress REM sleep. This article does not cite any references or sources. ... Benzodiazepine tablets The benzodiazepines are a class of drugs with hypnotic, anxiolytic, anticonvulsant, amnestic and muscle relaxant properties. ... An antidepressant is a medication used primarily in the treatment of clinical depression. ...

Initial studies associated lack of REM sleep with adverse consequences, backed up by animal studies which including the finding that REM deprivation is ultimately fatal to rats. However a number of studies on humans subsequently failed to confirm the findings, and the majority opinion is that REM deprivation has no ill effects. What is agreed is that suppressing REM sleep greatly increases the number of attempts the subject will make to enter REM sleep. Also once the suppression is stopped, the proportion of time spent in REM sleep will increase significantly, which is known as REM rebound[4].


  1. ^ KrygerM, RothT, Dement W. 'Principles & Pracitces of Sleep Medicine' WB Saunders Company. 2000: PG. 15, 724.
  2. ^ Sasaki Y; Fukuda K, Takeuchi T, Inugami M, Miyasita A (March 2000). "Sleep onset REM period appearance rate is affected by REM propensity in circadian rhythm in normal nocturnal sleep.". Clin Neurophysiol. 111 (3): 428-33. PMID 10699402. Retrieved on 2006-07-22. 
  3. ^ Siegel, Jerome M.. "The REM Sleep-Memory Consolidation Hypothesis". 
  4. ^ REM deprivation at Macalester College, Sleep deprivation.
  • Morrissey MJ, Duntley SP, Anch AM, Nonneman R. Active sleep and its role in the prevention of apoptosis in the developing brain. Med Hypotheses. 2004;62(6):876-9. PMID 15142640
  • Marks GA et al. A functional role for REM sleep in brain maturation. Behav Brain Res. 1995 Jul-Aug;69(1-2):1-11. PMID 7546299

Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 203rd day of the year (204th in leap years) in the Gregorian calendar. ...

See also

  Results from FactBites:
Sleep Stages - SleepChannel (0 words)
Rapid eye movement (REM) sleep is marked by extensive physiological changes, such as accelerated respiration, increased brain activity, eye movement, and muscle relaxation.
REM sleep is distinguishable from NREM sleep by changes in physiological states, including its characteristic rapid eye movements.
Rapid eye movement latency (the time it takes a person to achieve REM sleep) may be affected by a sleep disorder like narcolepsy.
Rapid Eye Movement Sleep | REM Sleep Disorder | Stages Of Sleep (718 words)
Rapid eye movement sleep is recurring sleep state during which dreaming occurs.
The later cycles have longer Rapid eye movement sleep periods and shorter deep sleep periods.
Infants are unique in that they spend approximately 50 percent of their sleep time in Rapid eye movement sleep.
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