Melatonin is a neurohormone produced during the night by the pineal gland. Its secretion is
regulated by circadian and seasonal variations in daylength, transmitted via visual
projections to the suprachiasmatic nucleus which functions as a circadian clock in mammals.
Melatonin has been proposed to act as an internal synchronizer of circadian rhythms
generated at different levels of the organism. The chronobiotic effects of melatonin in
humans have been mainly studied in circadian rhythm sleep disorders related to jet lag, shift …