FIGURE 1.

Melatonin regulation of peripheral clocks. All vertebrates synthesize and release melatonin through the pineal gland in a circadian‐dependent manner that has a classical peak during the night and is suppressed during the day. The nocturnal synthesis and release of melatonin are highly controlled by the master clock residing in the suprachiasmatic nucleus (SCN) through a fine molecular mechanism that is inhibited by light exposure. In turn, melatonin synchronizes peripheral clocks by acting at different levels and regulating several physiological functions. When melatonin synthesis and secretion are deregulated and/or desynchronized due to loss of master clock function, there is misalignment of peripheral clocks and a failure of physiological function control. Illustrations created with BioRender.com