The Development of Circadian Rhythms: From Animals to Humans

Increasing evidence indicates that the circadian timing system is a fundamental homeostatic system that potently influences human behavior and physiology throughout development. After birth there is progressive maturation of the circadian system with day-night rhythms in activity and hormone secretion developing between 1 and 3 months of age. Recent evidence shows that the circadian system of primate infants is responsive to light at very premature stages and that low-intensity lighting can regulate the developing clock. With the continued elucidation of circadian system development and influences on human physiology and illness, it is anticipated that consideration of circadian biology will become an increasingly important component of neonatal care.