The Suprachiasmatic Nucleus (SCN) is a small region of the hypothalamus that acts as the body's master oscillator. It receives light signals directly from the retina via the retinohypothalamic tract and synchronizes circadian rhythms throughout the organism.
Key Functions
- •Master clock — sets the phase for all peripheral clocks
- •Light input — photoreceptors in the retina send signals to the SCN
- •Output signals — regulates melatonin, cortisol, body temperature
- •Entrainment — adjusts to light-dark cycles (jet lag recovery)
In ONDA Life
The Circadian Reset protocols work with the SCN: morning light exposure triggers a timed Cortisol pulse and sets the timer for Melatonin release. Blocking blue light at night allows the natural shutdown sequence to initialize.