Hannibal, J. (2021). Action of Light on the Neuroendocrine Axis. In Neuroendocrine Clocks and Calendars. Masterclass in Neuroendocrinology, 10. Springer.
Abstract: Photoentrainment of the circadian clock located in the hypothalamic suprachiasmatic nucleus (SCN) is fundamental for the stable regulation of neuroendocrine function underlying physiological functions such as metabolism, sleep, immune responses, and reproduction. Masking by light directly suppresses melatonin secretion independent of the circadian system, with impact on several neuroendocrine axes. This chapter describes recent findings in anatomy and physiology on how light mediates its effects on SCN-regulated timing of the neuroendocrine system, including the hypothalamic-pituitary-adrenal (HPA) axis, the hypothalamic-pituitary-thyroid (HPT) axis, the hypothalamic-pituitary-gonadal (HPG) axis, and melatonin and arginine-vasopressin (AVP) secretion. In modern societies, artificial light at night (ALAN) seems to affect circadian and neuroendocrine systems, and should be considered in the understanding the health problems of the industrialized human population.