Melatonin is also used medically in a number of conditions, including radiation exposure, Alzheimer's disease, and tinnitus.
Produced in the pineal gland in the brain, melatonin helps control sleep-wake cycles. Some foods contain melatonin, and it is also available as a pill.
Of melatonin's many functions, the best understood is the part it plays in maintaining circadian rhythms. In humans, the circadian "clock" is found within the hypothalamus in an area called the suprachiasmatic nucleus (SCN). Using the daily cycle of light and dark, the SCN creates and maintains a daily cycle. Certain hormones are released at specific times of the day. In the late afternoon and early evening, hormones are released that prepare the body for sleep. During the early hours of the morning, the body starts to prepare for waking and activity....read more>>>...