What is the Origin of Sleep Wake Cycle Hormones?

This term is a clinical descriptor within neuroendocrinology, focusing on the subset of hormones whose secretion is directly controlled by the suprachiasmatic nucleus (SCN) and which serve as powerful internal signals for the sleep-wake state. It emphasizes the hormonal basis of the behavioral rhythm. The discovery of the distinct nocturnal and diurnal roles of these hormones cemented their importance in chronobiology.

What is the Mechanism of Sleep Wake Cycle Hormones?

The SCN, acting as the master clock, dictates the release patterns of these hormones. Melatonin secretion begins under dim light conditions (DLMO), signaling the biological night and promoting sleep initiation. Conversely, the HPA axis drives a peak in cortisol release shortly before and after Entrained Awakening, preparing the body for the metabolic demands of the day. This push-pull mechanism ensures that the body's physiological state aligns perfectly with the appropriate phase of the 24-hour cycle.

Sleep Wake Cycle Hormones ∞ Area

Sleep Wake Cycle Hormones

Meaning

Sleep Wake Cycle Hormones are the key endocrine messengers that rhythmically regulate the transition between alertness and rest, orchestrating the body’s daily energy and repair cycles. The primary hormones involved are melatonin, which promotes sleep onset, and cortisol, which promotes wakefulness and energy mobilization. The precise, antagonistic rhythm of these hormones is essential for maintaining a stable circadian rhythm and overall metabolic health.