Rapid Eye Movement Sleep during Early Life: A Comprehensive Narrative Review

Abstract

The ontogenetic sleep hypothesis suggested that rapid eye movement (REM) sleep is ontogenetically primitive. Namely, REM sleep plays an imperative role in the maturation of the central nervous system. In coincidence with a rapidly developing brain during the early period of life, a remarkably large amount of REM sleep has been identified in numerous behavioral and polysomnographic studies across species. The abundant REM sleep appears to serve to optimize a cerebral state suitable for homeostasis and inherent neuronal activities favorable to brain maturation, ranging from neuronal differentiation, migration, and myelination to synaptic formation and elimination. Progressively more studies in Mammalia have provided the underlying mechanisms involved in some REM sleep-related disorders (e.g., narcolepsy, autism, attention deficit hyperactivity disorder (ADHD)). We summarize the remarkable alterations of polysomnographic, behavioral, and physiological characteristics in humans and Mammalia. Through a comprehensive review, we offer a hybrid of animal and human findings, demonstrating that early-life REM sleep disturbances constitute a common feature of many neurodevelopmental disorders. Our review may assist and promote investigations of the underlying mechanisms, functions, and neurodevelopmental diseases involved in REM sleep during early life.

Women’s mood at high altitude. sexual dimorphism in hypoxic stress modulation by the tryptophan–melatonin axis

“…REM sleep, thought to support CNS maturation and optimization ( Chen et al, 2022 ), tends to decrease on exposure to cold ( Komagata et al, 2019 ). 5-HT neurons lead BAT to enhance heat generation by increasing the sympathetic drive ( Yabut et al, 2019 ).…”

The Ponto-Geniculo-Occipital (PGO) Waves in Dreaming: An Overview

“…More recently, the concept of REM sleep regulation has evolved. Several hypothalamic and forebrain networks, including newly identified neuropeptides such as orexin and melanin-concentrating hormone (MCH), have been implicated in both the control and the final expression of this behavioral state [ 14 , 16 , 17 , 49 , 50 , 51 , 52 , 53 , 54 ]. Firstly, a reciprocal interaction between REM on and REM off states has been proposed to occur in the brainstem.…”

“…Next, in the hypothalamus, orexinergic neurons are generally REM-off and are suppressed during REM sleep [ 57 ]. A deficiency in this process may be a cause of narcolepsy [ 16 , 17 ]. MCH neurons act as REM-on neurons and play an important role in REM sleep onset and maintenance [ 16 ].…”

“…PGO waves during REM sleep in development might be an important central nervous system (CNS) stimulator during a period when wakefulness is limited in time and scope and stimulation opportunities are few [ 94 , 97 , 98 ]. The ascending impulses emanating from the brainstem during REM sleep may be required to promote neuronal differentiation, maturation, and myelination in higher brain centers [ 17 ]; that is, REM sleep deprivation during the early life of animals has been used to understand some functional mechanisms of PGO waves in brain development. Selective REM sleep deprivation further eliminates the endogenous stimulation of PGO waves [ 17 ].…”

“…During REM sleep, in addition to rapid eye movements (REMs), cortical electroencephalogram (EEG) desynchronization (or activation), loss of muscle tone, and autonomic fluctuations [ 2 , 3 , 4 , 5 ], many other physiological and behavioral features have also been found in humans and other mammals. These include high-amplitude spiky potentials of ponto-geniculo-occipital (PGO) waves, high-amplitude hippocampal EEG theta waves, penile erections, sporadic limb twitching, increases in brain/body temperature, and an elevated arousal threshold [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ]. In these characteristic components of REM sleep, PGO waves are undoubtedly powerful internal sensory signals that convey a large amount of information to the visual cortex and seem to “compose the song sheet of dreams” [ 18 ].…”