There are a lot of studies going on right now in humans that look at melatonin's ability to help with jet lag as well as with delayed sleep syndrome. People with delayed sleep syndrome can't get to sleep until very late, sometimes until the wee hours of the morning, and then they need to sleep until late in the day. In studies where those people are given melatonin right before a normal bedtime, the melatonin appears to advance the phase of their circadian clock so that they can go on to sleep. Prosser's careful exploration and manipulation of the circadian clock has already led to some useful insights. She and a Scripps Institute researcher collaborated to confirm the existence of a serotonin receptor that is specific to the circadian clock area of the brain.
Serotonin acts through that receptor to shift the clock.
Researchers are trying to come up with serotonin drugs that specifically target this receptor. We're trying to figure out how to manipulate the circadian clock, and if we can do that, there are very direct applications to humans in terms of helping with jet lag, shift work, and sleep problems.