Melatonin is a naturally produced molecule that has long been suspected to play a role in healthy sleep, but it has been unclear how it does so. Now, Caltech researchers have discovered a mechanism through which melatonin promotes sleep, using zebrafish models in the laboratory. The research was conducted in the lab of Professor of Biology David Prober and is described in a paper appearing in Current Biology on April 20. Sleep is a vital and evolutionarily ancient behavioral state, yet there are still many open scientific questions about how sleep is regulated by the body, and there are few effective therapies for sleep disorders. To understand the mechanisms by which sleep is regulated, the Prober lab is using an unusual lab animal: zebrafish. There are several advantages for using zebrafish as a sleep model, including that their brains are simpler than ours but still similar.…