Melatonin, which is naturally produced in the brains, contributes to fall asleep naturally, revealed a research conducted by California Institute Of Technology. Researchers explained that when one starts feeling tired then two mechanisms helps to believe the fact, one was homeostatic mechanism which responds to the body's internal cues for sleep, and a circadian mechanism that responds to external cues such as darkness and light.
David Prober, assistant professor of Biology said, "Before our study people knew that supplemental melatonin could help to promote sleep, but they didn't know what naturally occurring melatonin normally does in the body. Our findings showed that melatonin, that was produced in the pineal gland normally played an important role in sleep and that one required this natural melatonin to fall asleep and to stay asleep."
The researchers observed that mutation-induced sleep reduction was actually due to a lack of melatonin. They used a drug to kill the cells of the pineal gland, which would halt the hormone's production. As a result of usage of drug, reduction of sleep was noticed and after stopping the usage the natural sleeps regenerate.
The study is published in the journal Neuron.