The role of hypoxia in sleep, and its function as a precursory etiologic mechanism for the REM state: a hypothesis.

Sleep is a restorative hypoxic process annuling the effects of the potentially toxic products of aerobic metabolism. The REM state is characterized by the desynchronized homeostasis resulting from the hypoxia (hypoxemia and possible localized anoxia) which alerts the organism. Compensatory increase in respiration occurs, and the organism recovers from the threat of possible anoxic asphyxiation. The cyclic hypoxia (deep sleep) and desynchrony (REM state) and recovery from hypoxia repeat as the different stages of sleep till a homeostatically acceptable recovery from the metabolic burden of aerobic oxidation of waking is achieved.