Learning & education: chronobiology
Melatonin is widely regarded as an important hormone that helps regulate and synchronize sleep rhythm, including sleep-wake timing [1] and seasonal rhythmicity aspects across vertebrates. It also has lesser-known roles as an antioxidant [2]. We have touched briefly on melatonin in a previous article about sleep hormones and their effect on the GABA system here.
There are various types of biological clocks in the body, including circadian, ultradian, and infradian. These will be discussed in depth below, but suffice to say that they serve to control a vast array of physiological processes in the body and ensure that everything runs smoothly [2].