Melatonin and Sleep: Possible Involvement of GABAergic Mechanisms

Pineal melatonin is synthesized and secreted in close association with the light/dark cycle. The temporal relationship between the nocturnal rise in melatonin secretion and the “opening of the sleep gate” (i.e., the increase in sleep propensity at the beginning of the night), coupled with the sleep-promoting effects of exogenous melatonin, support the view that endogenous melatonin is involved in the regulation of sleep. The sleep-promoting and …