Abstract
This was the "News & Views" story in the journal Nature that was most popular online in 2020. The relative contribution of stress to greying of the hair is not known. Hair color is determined by melanocyte cells derived from melanocyte stem cells (MeSCs) located in a part of the hair follicle called the bulge. This paper, published in Nature in January 2020, was authored by Ya-Chieh Hsu's research group at Harvard University, with Bing Zhang as the first author [1]. Zhang et al. report that noradrenaline - a neurotransmitter molecule involved in the "fight or flight" response to stress - is released from neurons of the sympathetic nervous system. MeSC proliferation and differentiation increase markedly under extreme stress or on exposure to a high level of noradrenaline, resulting in a mass migration of melanocytes away from the bulge and leaving no remaining stem cells to replace them,(①) thus causing greying. This work by Zhang et al. provides a better understanding of how stress influences other stem cells as well as clues for finding ways to stop and reverse the effects of stress.