摘要
In the central nervous system(CNS),the suprachiasmatic nucleus(SCN)integrates signals from the body with light cues(Zeitgeber),which specialized retinal cells recognize(Fig.1A)[1].This allows for the coordination of daily physiological and behavioral rhythms in roughly a 24-hour cycle[2].While light serves as the primary signal for synchronizing the body with the external environment,constant exposure to light can disrupt the circadian system.Shift workers,for example,are a group at risk for experiencing such disruptions in both central and peripheral circadian rhythms of clock genes.While light strongly disrupts the sleep-wake cycle due to SCN arrhythmicity,constant darkness alters this system with minimal environmental interference and provides a model for studying its intrinsic properties[1-3].
