According tomedia New Atlas, chicken skins are a strange reaction to our bodies that scientists don’t fully understand. Now, researchers at Harvard University have discovered the biological cause of this reaction: this is how our bodies stimulate stem cells to drive new hair growth.
We are all familiar with chicken skins. When you feel cold or scared, your skin will appear small moles and sweaty hair will rise. But why is this happening? One theory is that it was left behind by the evolution of human ancestors. At that time, the reaction of the fine hair tissue will help people warm up. But because it doesn’t really help humans with rare hair, scientists want to know why it persists today. So in the new study, the Harvard team looked at the cellular level to see if it could have other benefits.
In mice tests, the researchers found a potential purpose. Cells that cause goose bumps have also been shown to play a key role in regulating stem cells that regenerate hair and hair follicles. This effect is enhanced when the low temperature time is extended. This means that pickling chicken skins is basically a short-term solution, while the body tries to stimulate new hair growth to keep us warm for long.
“This particular response helps to couple tissue regeneration with changes in the outside world, such as temperature,” said Yulia Shwartz, co-lead author of the study. “It’s a two-tiered reaction: pick-up is a quick way to provide some relief in a short period of time. But as the cold continues, it becomes a good mechanism for stem cells to know that maybe it’s time to regenerate new hair. “
The general cellular mechanism behind chicken skins has long been known. When the weather gets cold, the sympathetic nerve shrinks a small muscle attached to the bottom of the hair follicle. This will tighten it up, causing the sweat to rise up. It also causes the skin around the hair to pull inward, which is why it produces a bumpy texture, which is its name. But the team found a new part of the equation. Using an electron microscope to examine the skin, they found that sympathetic nerves were also directly linked to hair follicle stem cells, encased in them. When the nerve is activated, it also activates stem cells and begins to grow new hairs.
“We can really see how nerves and stem cells interact at the ultrastructure level,” said Ya-Chieh Hsu, co-lead author of the study. “Neurons tend to regulate excitatory cells, just like other neurons or muscle synapses. But we were surprised to find that they formed a similar synaptic structure to an epithelial stem cell, which is not a very typical target for neurons. “
The researchers plan to continue to explore how the external environment also affects stem cells in the skin.
The study was published in the journal Cell.