Abstract:

Melatonin plays important roles in modulating brain function especially in the entrainment of the sleep/wake cycle. This occurs in the suprachiasmatic nucleus of the hypothalamus (master biological clock) through melatonin receptors, MT₁(MT₁R ) and MT₂(MT₂R) and the coordinated release of melatonin from the pineal gland that result in peak nocturnal levels of circulating melatonin followed by daytime troughs [1]. Besides sleep, melatonin, acting through melatonin receptors, affects the release of hypothalamic/pituitary hormones involved in reproduction and stress [2-4] and modulates other brain centers involved in pain and blood pressure [5-8]. Though these areas of study are important and affected by age, the focus of this review will be on the role of melatonin and melatonin receptors in brain function greatly impacted by age, with an emphasis on those affecting memory, mood, and movement.The cellular mechanisms underlying melatonin and melatonin receptor action will be discussed in the context of the literature but also will highlight other potential targets to guide future studies in this area.