The Ontogenetic Development of Rapid Eye Movement Sleep in Early Life and Its Regulatory Mechanisms

Rapid eye movement (REM) sleep, also known as paradoxical sleep (PS), was first identified in humans and cats in the late 1950s. It is hypothesized to contribute to brain development by providing endogenous neural activity patterns that coincide with critical periods of maturation. We summarize the remarkable alterations in polysomnographic data, EEG power spectral analysis, and behavioural patterns during early-life REM sleep, as well as the subsequent maturation of these features and the development of regulatory mechanisms. REM sleep disturbances in early life are linked to neurodevelopmental disorders. Our review aims to elucidate changes in the main characteristics during REM sleep development and its evolutionary connection with brain development, ultimately providing a basis for promoting the prevention and treatment of various neurodevelopmental disorders.