ABOVE: Stressed mice go gray because nerves in the sympathetic nervous system (pink) trigger the proliferation, differentiation, and subsequent depletion of stem cells called melanocytes (yellow), which are converted into the cells that give hair its color.
BING ZHANG AND YA-CHIEH HSU
Stress definitely does turn hair gray—in mice, at least.
Researchers have found that stress triggers the fight-or-flight response, which damages the cells that ultimately give skin and hair its color and leads to the cells’ depletion. In experiments, dark-furred mice that were stressed turned white in just days, the team reported yesterday (January 22) in Nature.
Folklore has long suggested that stress could strip the color from even the richest reds, blondes, and browns, but how it happens has been a mystery. “It was satisfying to question a popular assumption . . . [and] to identify the mechanisms that now open up new areas of work,” Ya-Chieh Hsu, a ...
