Neurobiology of sleep (Review)

Summary & key facts

This review explains how the brain controls sleep. It says sleep has two main phases (NREM and REM), and that genes, cells, brain areas, and chemical messengers all work together to switch the brain between being awake and sleeping. It also describes a tiny brain clock that uses signals like light to help set daily sleep–wake patterns.

Key facts:

• The paper is a review that pulls together many studies about how sleep is controlled, rather than reporting a new experiment.
• Sleep is made of two main phases: non-rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep.
• Control of sleep happens at many levels: genetic, cellular, and whole-brain systems.
• Several specific brain areas help regulate sleep and waking. These include the basal forebrain, the thalamus, and the hypothalamus.
• Many brain chemicals (called neurotransmitters) help promote either wakefulness or sleep. The review names serotonin, norepinephrine, histamine, hypocretin (also called orexin), acetylcholine, dopamine, glutamate, and gamma‑aminobutyric aci
• A small brain region called the suprachiasmatic nucleus acts like a central pacemaker, taking in environmental cues and helping coordinate the body and brain to the daily sleep–wake pattern.
• The review describes several models that try to explain how the brain moves between wakefulness, NREM, and REM sleep. All of these models rely on networks of brain regions and the neurotransmitters listed above.
• Because the review ties environmental cues and a central clock to sleep timing, it helps explain why factors like light and daily schedule are linked with when people feel sleepy or awake. The paper does not make treatment or medical advice

Abstract

Sleep is a physiological global state composed of two different phases: Non-rapid eye movement (NREM) and rapid eye movement (REM) sleep. The control mechanisms of sleep manifest at the level of genetic, biological and cellular organization. Several brain areas, including the basal forebrain, thalamus, and hypothalamus, take part in regulating the activity of this status of life. The signals between different brain regions and those from cortical areas to periphery are conducted through various neuromediators, which are known to either promote wakefulness or sleep. Among others, serotonin, norepinephrine, histamine, hypocretin (orexin), acetylcholine, dopamine, glutamate, and gamma-aminobutyric acid are known to orchestrate the intrinsic mechanisms of sleep neurobiology. Several models that explain the transition and the continuity between wakefulness, NREM sleep and REM sleep have been proposed. All of these models include neurotransmitters as ligands in a complex reciprocal connectivity across the key-centers taking part in the regulation of sleep. Moreover, various environmental cues are integrated by a central pacemaker-located in the suprachiasmatic nucleus-which is able to connect with cortical regions and with peripheral tissues in order to promote the sleep-wake pattern.

Topics

Circadian rhythm and melatonin Sleep and related disorders Sleep and Wakefulness Research

Categories

Cognitive Neuroscience Life Sciences Neuroscience

Tags

Basal forebrain Biochemistry Biology Central nervous system Computer science Electroencephalography Eye movement Hypothalamus Narcolepsy Neurology Neuropeptide Neuroscience Neuroscience of sleep Non-rapid eye movement sleep Operating system Orexin Psychology Receptor Sleep (system call) Suprachiasmatic nucleus Thalamus Wakefulness

Conditions & symptoms

Sleep disorder Lack of energy or motivation Poor sleep