Light and Life at Night as Circadian Rhythm Disruptors

Abstract

The axial rotation of the Earth, together with the light of the sun, generates 24-hour cycles of day and night, and this light-dark cycle is the basis of 24-hour circadian rhythms. Living organisms have their own endogenous circadian rhythms, also with a duration of approximately 24 hours, driven by environmental factors, especially light and darkness [1]. And it is widely known that circadian rhythms of mammals are regulated by an internal biological clock located in the suprachiasmatic nuclei (SCN) situated directly above the optic chiasm [2]. Maintaining the biological clock is crucial for coordinated function throughout the human body because this near-24-hour oscillations are found in essentially every physiological process in the human brain and body [3,4]. The period, phase and amplitude of circadian rhythms can be affected by circadian gene variants, light exposure, social cues, meal times and work schedules [5-8]. Light is the most effective Light and Life at Night as Circadian Rhythm Disruptors