In the journal Nature, an article with the solution to a biological puzzle appeared: scientists at Harvard University have discovered why Stress makes hair grey.
There are many anecdotes from people who are supposed to be graying overnight. Researchers at Harvard University have now discovered how this process takes place in the Individual: Stress activates the sympathetic nervous system for fight or flight response is responsible. This leads to a permanent damage of the pigment regeneration stem ends of the follicle cells in the hair.
Quite simply, the thing was, because the researchers are initially trapped in two dead-ends: they assumed that an immune attack damages the pigment-producing cells. But mice in which immune cells were missing, were, nevertheless, gray hair. Then they turned to the stress hormone Cortisol, which could exclude but also as a perpetrator, because again, gray mice without Cortisol.
The cause lies in the sympathetic nervous system
Finally, they found follicles on sympathetic nerves in the hair. Stress causes these nerves, the hormone norepinephrine to be released which is absorbed by the stem cells, the pigment-forming cells produce. Norepinephrine led to an excessive activation of the stem cells, whereupon all in the pigment-producing cells are transformed, so that the Reservoir has been prematurely exhausted. Harvard Professor Ya-Chieh Hsu said: "After just a few days, all of the pigment regeneration were lost stem cells. As soon as you are gone, can be formed no Pigment anymore. The damage is permanent."