Circadian rhythm disruption in bipolar disorder: Mechanisms, clinical significance, and rhythm-oriented interventions

Figure 1 Molecular mechanisms and physiological regulation of the human circadian rhythm system. The central clock, located in the suprachiasmatic nucleus of the hypothalamus, maintains circadian rhythms through a hierarchical network of molecular clock genes composed of core clock genes such as CLOCK and BMAL1. The suprachiasmatic nucleus receives photic input and other environmental zeitgebers via the retinohypothalamic tract and coordinates whole-body rhythmic synchronization through endocrine and neural signals, thereby regulating the peripheral clock. SCN: Suprachiasmatic nucleus.