The dream of rapid eye movement (REM sleep, REMS) is a phase unique sleep in mammals and birds, distinguishable by random motion / fast eye, accompanied by low muscle tone throughout the body and the propensity of the sleeper to dream vividly.
The REM phase is also known as paradoxical sleep (PS) where sleep is sometimes out of sync due to the physiological similarities it has to waking states, including fast, low-voltage desynchronized brain waves. The electrical and chemical activity that regulates this phase appears to originate in the brain stem and is characterized primarily by an abundance of the neurotransmitter acetylcholine, combined with an almost complete absence of the neurotransmitters monoamine, histamine, serotonin, and norepinephrine.
REM sleep is physiologically different from the other phases of sleep, which are collectively called non-REM sleep (NREM sleep, NREMS, synchronized sleep). REM and non-REM sleep alternate within a sleep cycle, which lasts approximately 90 minutes in adult humans. As sleep cycles continue, they shift toward a higher proportion of REM sleep. The transition to REM sleep brings marked physical changes, beginning with electrical bursts called PGO waves that originate in the trunk.encephalic. Organisms in REM sleep suspend central homeostasis, allowing large fluctuations in respiration, thermoregulation, and circulation, which do not occur in any other mode of sleeping or waking. The body abruptly loses muscle tone, a state known as REM atony.
Professor Nathaniel Kleitman and his student Eugene Aserinsky were the ones who defined rapid eye movement and linked it to dreams in 1953. REM sleep was described by researchers such as William Dement and Michel Jouvet. Many experiments have involved the awakening of test subjects each time they begin to enter the REM phase, thus producing a state known as REM deprivation. Subjects who are allowed to sleep normally again generally experience modest REM rebound. The techniques of neurosurgery, chemical injection, electroencephalography, positron emission tomography and reports of waking dreamers have been used to study this phase of sleep.
