in solving the biological puzzle, scientists from Harvard University have established that stress causes gray hair through a previously unknown connection between the nervous system and stem cells that regenerate the pigment that gives hair its color. his has been drawn out from a study of rodents.
The biologists discovered that with mice, a type of nerve connected to stress (or the fight-or-flight response) triggers permanent changes to the pigment-regenerating stem cells located within a hair follicle. The research indicates how stress can impact upon the body. As well as being of general interest, the findings could assist with advancing medical understanding in terms of finding ways to counteract the negative effects of stress upon the body.
The primary trigger for graying hair was traced to a sympathetic nerve system, one that is responsible for the body’s fight-or-flight response. These nerves feed into each hair follicle on the skin. The scientists discovered that moments of stress trigger the nerves into releasing the chemical norepinephrine. This chemical then gets taken up by nearby pigment-regenerating stem cells.
An examination showed how the release of norepinephrine from sympathetic nerves leads to stem cells activating excessively. Under these conditions, the stem cells convert into pigment-producing cells, prematurely depleting the reservoir.
These findings could pave the way for a deeper understanding into the ways in which stress influences other tissues and organs in the body. From this it may be possible to develop medication to counter the affect of stress on different parts of the human body, thereby lowering the detrimental impact of stress.
The research has been published in the science journal Nature. The science paper is titled “Hyperactivation of sympathetic nerves drives depletion of melanocyte stem cells.”
