Mechanisms of Circadian Rhythm Regulation in Humans

Significant progress was made in the past decade in understanding the mechanisms that regulate the circadian rhythms and, in particular, the sleep–wake cycle. In the light of new data, the regulation of the sleep–wake cycle is a multilevel process that involves various systems and functional clusters of the body to trigger and maintain wakefulness or slow-wave and REM sleep. The review summarizes information about the above mechanisms; bioenergetic processes in the brain; and the regulation of synaptic homeostasis, the immune system, glymphatic clearance, etc. Although a target of therapeutics in many diseases, sleep remains one of the main mysteries that the scientific community is facing.