Processes underlying sleep regulation

Abstract

Sleep is regulated by homeostatic, circadian and ultradian processes. Slow waves and sleep spindles are EEG markers of sleep processes which have counterparts at the cellular level. The interaction of homeostatic and circadian sleep regulation has been formalized in the two-process model and validated in experiments. Sleep is not only a global brain phenomenon but also a regional cerebral process whose intensity may be influenced by prior activity during waking.