How Melatonin Promotes Sleep

Melatonin is the hormone that promotes sleep.  University of Missouri School of Medicine researchers have recently discovered the way that melatonin suppresses brain neurons that keep you awake.  Mahesh Thakkar, PhD, the lead author of the study, says that nothing is more important than getting quality sleep.

The research used a mouse as a model.  Thakkar discovered that when melatonin was placed in the brain of a mouse at dark (dark is when a mouse is awake & active), it increased sleep time and decreased awake time.  The melatonin suppressed certain brain neurons that make the brain become alert.  Also, the research showed that blocking melatonin brain receptors at bedtime increased wakefulness in the mouse. The experiments found that one receptor, MT1, was the mechanism through which the melatonin acted to inhibit specific neurons that wake you up. This discovery could lead to new medications that target only this MT1 receptor and could mean fewer side effects.

For a long time, melatonin has been used as a sleep medication and we did not know how it worked. Now we have a better idea of the mechanism.  The study, “Melatonin Promotes Sleep in Mice by Inhibiting Orexin Neurons in the Perifornical Lateral Hypothalamus,” can be found the Journal of Pineal Research.

We also know that in stage 4 of the sleep cycle, serotonin is produced.  And melatonin is made from this serotonin.  So, if you are not getting into stage 4 of sleep for 90 minutes total during the night, you won’t have enough serotonin produced and therefore won’t have enough melatonin produced.  This is typical in patients with obstructive sleep apnea which can be easily diagnosed with a home sleep test.  If you have trouble getting to sleep, staying asleep, or getting back to sleep, you may be suffering from obstructive sleep apnea.  Two of the most common symptoms of apnea are snoring and daytime tiredness.  If you have any questions about your sleep problems, you can make a free consultation appointment at my office to discuss them.