'Fight or Flight' Nerves Make Mice Go Gray
This is scientific Americans. Sixty seconds science. I'm Karen Hopkins. They say that Marie Antoinette's hair turned white the night before she lost her head to the guillotine but constraints really have such a dramatic effect on hair-color a new study in mice concludes at Ken and credits overactive. Nerves with stripping the color from the animals locks and possibly hours researchers at Harvard Stem Cell Institute. Were interested in these stress and hair color issue so they decided to take a closer look at the stem cells that give rise to Milan. Ascites the cells that pump pigments into each hair follicle stem cells. Were an obvious target. Because changes in the stem cell population translates to try and justify hair color which very visible and easy to identify. Jacek sue the study senior author to start. She and her colleagues subjected mice to some rodent sized stressors like having their cage tilted their bedding dampened or their lights left on all night. So what did we find? We found stress indeed leads to premature hair grain in mice by took a long time for us to actually narrow down how occurs first they thought it could be the immune system attacking the millennia site stem cell population however mayes lack immune cells steel. Shell premature here graying under stress than they thought the key factor could be cortisol. The quintessential stress hormone the one way removed from the mice so that they cannot produce quarter so like her mows. The hairstyle turned gray under stress. That's when they turn their attention to the sympathetic nervous system which or constraints the body's overall reaction to stress including the classic fight or flight. Response those nerves reach out to our muscles organs and yes even our hair the nerve terminals wrap around each follicle like a ribbon and sooner team cut. Those connections the stem cells were spared and the animals kept their shiny black coat even in the face of minor discomfort. The findings appear in the journal Nature. It's unclear whether the same sympathetic nerves make us gray as we age but the results provide hope that we may someday be able to fight to hold onto our natural hair color and avoid that monthly flight to the hairdresser. Thanks for listening. For Scientific Americans sixty seconds science. I'm Karen Hopkin.