NationMaster - Encyclopedia: REM atonia

Rapid eye movement (REM) is the stage of sleep characterized by rapid saccadic movements of the eyes. During this stage, the activity of the brain's neurons is quite similar to that during waking hours. Most of the vividly recalled dreams occur during REM sleep. It is the lightest form of sleep, and people awakened during REM usually feel alert and refreshed. Jump to: navigation, search In an ideal situation, sleep should be undisturbed and experienced in the same room every night Sleep is the regular state of natural unconsciousness observed in all mammals, birds and fish. ... This article does not cite its references or sources. ... An eye is an organ that detects light. ... In the anatomy of animals, the brain, or encephalon, is the higher, supervisory center of the nervous system. ... Neurons (also spelled neurones or called nerve cells) are the primary cells of the nervous system. ... Dreaming is the subjective experience of remembered and imaginary images, sounds/voices, words, thoughts or sensations during sleep, usually involuntarily. ...

REM sleep is so physiologically different from the other phases of sleep that the others are collectively referred to as non-REM sleep. The NREM (non-rapid eye movements) is a sleeping period without rapid eye movement (REM). ...

During a night of sleep, a person usually has about four or five periods of REM sleep, which 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 total time of REM sleep per night is about 90-120 minutes.

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. ... Polysomnography is the multi-parametric test used in the study of sleep. ... Electroencephalography is the neurophysiologic exploration of the electrical activity of the brain by the application of electrodes to the scalp. ...

Physiology of REM sleep

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. The lack of REM atonia causes REM Behavior Disorder; sufferers act out the movements occurring in their dreams. Jump to: navigation, search The brain stem is the stalk of the brain below the cerebral hemispheres. ... The pontine tegmentum is a part of the pons of the brain involved in the initiation of REM sleep. ... Neurotransmitters are chemicals that are used to relay, amplify and modulate electrical signals between a neuron and another cell. ... In biochemistry, monoamines are a group of organic compounds containing only one amino group. ... Norepinephrine, known as noradrenaline outside the USA, is a catecholamine and a phenethylamine with chemical formula C8H11NO3. ... Serotonin (5-hydroxytryptamine, or 5-HT) is a monoamine neurotransmitter synthesised in serotonergic neurons in the central nervous system and enterochromaffin cells in the gastrointestinal tract. ... Histamine is a biogenic amine chemical involved in local immune responses as well as regulating physiological function in the gut and acting as a neurotransmitter. ... In vertebrates, motoneurons (also called motor neurons) are efferent neurons that originate in the spinal cord and synapse with muscle fibers to facilitate muscle contraction and with muscle spindles to modify proprioceptive sensitivity. ... Jump to: navigation, search A top-down view of skeletal muscle Muscle is a contractile form of tissue. ... 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, and it approaches that of the surroundings. Erections of the penis or clitoris are also common during REM. Jump to: navigation, search Heart rate is a term used to describe the frequency of the cardiac cycle. ... For the play Breath by Samuel Beckett, see Breath (play). ... Jump to: navigation, search This article needs to be cleaned up to conform to a higher standard of quality. ... Jump to: navigation, search The penis (plural penises) or phallus (plural phalli) is the external male copulatory organ of some animals, and, in mammals, the external male organ of urination. ... Jump to: navigation, search A womans clitoris extends from the visible portion to a point below the pubic bone. ...

The eye movements associated with REM are generated by the lateral geniculate nucleus and are associated with PGO (pons, geniculate, occipital) waves. An eye is an organ that detects light. ... Jump to: navigation, search The lateral geniculate nucleus (LGN) of the thalamus is a part of the brain, which is the primary processor of visual information, received from the retina, in the CNS. Schematic diagram of the primate lateral geniculate nucleus. ...

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). However, in people that have no REM sleep (because of brain damage), memory functions are not measurably affected. Jump to: navigation, search Memory is a function of the brain: the ability to retain information. ... 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. Jump to: navigation, search Clinical depression is a health condition of depression with mental and physical components reaching criteria generally accepted by clinicians. ... An antidepressant is a medication designed to treat or alleviate the symptoms of clinical depression; antidepressants function generally by interacting with the neurotransmitters (signalling chemicals) in the brain believed to influence mood. ...

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; in the dolphin, whose newborns are almost completely functional at birth, there is almost no REM sleep. Jump to: navigation, search Orders Subclass Multituberculata (extinct) Plagiaulacida Cimolodonta Subclass Palaeoryctoides (extinct) Subclass Triconodonta (extinct) Subclass Placentalia Afrosoricida Artiodactyla Carnivora Cetacea Chiroptera Creodonta (extinct) Dermoptera Desmostylia (extinct) Embrithopoda (extinct) Hyracoidea Insectivora Lagomorpha Litopterna (extinct) Macroscelidea Notoungulata (extinct) Perissodactyla Pholidota Primates Proboscidea Rodentia Scandentia Sirenia Tubulidentata Xenarthra Subclass Marsupialia Dasyuromorphia... For other meanings of bird, see bird (disambiguation). ... Jump to: navigation, search This article is about the mammal. ... Jump to: navigation, search Genera See article below. ...

History

The association between dreaming and REM sleep was discovered by Eugene Aserinsky and Nathaniel Kleitman in 1953. Eugene Aserinsky was a graduate student at University of Chicago in 1952 when he discovered REM sleep. ... Jump to: navigation, search 1953 is a common year starting on Thursday. ...

Sources

Contents

Physiology of REM sleep

Theories about the function(s) of REM sleep

REM sleep in other animals

History

Sources

See also

Contents

Physiology of REM sleep GA_googleFillSlot("encyclopedia_square");

Theories about the function(s) of REM sleep

REM sleep in other animals

History

Sources

See also

Physiology of REM sleep