July 10, 2020

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Aim for Excellence

‘Fight or Flight’ Nerves Make Mice Go Gray

They say that Marie Antoinette’s hair turned white the evening before she missing her head...

They say that Marie Antoinette’s hair turned white the evening before she missing her head to the guillotine. But can strain actually have this kind of a extraordinary effect on hair coloration? A new study in mice concludes that it can…and credits overactive nerves with stripping the coloration from the animals’ locks—and quite possibly ours.

Researchers at Harvard’s Stem Cell Institute have been fascinated in the strain and hair coloration issue. So they made a decision to choose a closer search at those people stem cells that give increase to melanocytes…the cells that pump pigments into each individual hair follicle. The stem cells have been an clear target…

“Because adjustments in the stem cell populace translate to adjustments in hair coloration which are really seen and easy to establish.”

Ya-Chieh Hsu, the study’s senior author.

To start off, she and her colleagues subjected mice to some rodent-sized stressors…like getting their cage tilted, their bedding dampened, or their lights remaining on all evening. 

“So what did we find? We observed that strain in fact leads to premature hair graying in mice. But it took a lengthy time for us to actually narrow down how it occurs.”

Very first they believed it could be the immune method attacking the melanocyte stem cell populace.

“However, mice missing immune cells continue to demonstrate premature hair graying below strain.”

Then they believed the essential variable could be cortisol…the quintessential strain hormone.

“But when we taken out the adrenal glands from the mice so they are not able to create cortisol-like hormones, their hair continue to turned gray below strain.”

That’s when they turned their consideration to the sympathetic anxious system…which orchestrates the body’s over-all response to strain, like the common combat or flight reaction. Individuals nerves arrive at out to our muscle tissue, organs, and…yes…even our hair.

“The nerve terminals wrap all-around each individual hair follicle like a ribbon.”

And when Hsu and her group slice those people connections, the stem cells have been spared and the animals kept their shiny black coat even in the deal with of minimal soreness. The results show up in the journal Character. [Bing Zhang  et al, Hyperactivation of sympathetic nerves drives depletion of melanocyte stem cells]

It is unclear whether the identical sympathetic nerves make us gray as we age. But the benefits give hope that we may well someday be equipped to combat to hold on to our pure hair color…and stay away from that regular monthly flight to the hairdresser. 

—Karen Hopkin 

[The over text is a transcript of this podcast.]