Cell: Uncovering the strong link between chicken skins and "vulture-proofing"...

When will it make you get goose bumps? Answer: A chill makes you shiverHas anyone thought about why we get goose bumps? If you've ever been so congratulated! Because, like Darwin, he thought about the goose bumps in his work on the skinIn some animals, goose bumps may protect them from the cold, but humans don't seem to benefit much from this reactionSo why has it been preserved in the course of evolution? In a recent study published in the journal Harvard University in the United States, scientists from harvard university in the United States give us some surprising clues: The type of cells that cause the skins of chickens is also important for regulating stem cells that regenerate hair follicles and hairIn short, there is a strong connection between chicken skinand and "baldness"Shrinking the muscles under the skin that produce goose bumps are the bridge between the sympathetic nerves and the hair follicle stem cellsThe role of sympathetic nerves is to contract muscles when we feel silky chills and cause a reaction of chicken skins and hair erectilesOf course, this is only a short-term effectIts long-term role is to drive the activation of hair follicle stem cells and grow new hairBecause the muscles (pink) in the hair follicles in the cold short term will contract and cause goose bumpsIn prolonged cold, sympathetic nerves (green) release neurotransmitters against hair follicle stem cells (blue) to activate and grow new hairThe findings in mice give researchers a better understanding of how different types of cells interact to link stem cell activity to changes in the outside environment"We've always been interested in understanding how external stimuli regulate the behavior of stem cells, " said the study's author, associate professor of stem cell and regenerative biologyThe skin is a fascinating system that separates our bodies from the outside world and has many types of stem cellsAs a result, they may react to various stimuli from the ecological niche to the entire body and even the external environmentIn this study, we found an interesting two-component habitat that regulates stem cells not only in a stable state but also in terms of stem cell behavior based on changes in external temperature"Many organs of the system that regulate hair growth are made up of epithelial, interstitial and nerves In the skin these three tissues are arranged in a special way Sympathetic nerves are part of our nervous system and it controls the body's steady state and our response to external stimuli It is connected to a small smooth muscle in the meth and hair follicle stem cells connected to hair follicle stem cells is an epithelial stem cell that is essential for hair follicle regeneration and wound repair The link between sympathetic nerves and muscles is well known because they are the cellular basis behind the goose bumps: cold triggers sympathetic nerve cells to send nerve signals to muscles through contraction and cause hair to respond upright However, when examining the skin at very high resolution with an electron microscope, the researchers found that sympathetic nerves were not only associated with muscles but also directly related to hair follicle stem cells In fact, nerve fibers are wrapped in hair follicle stem cells like ribbons "We can really see how nerves and stem cells interact at the superstructure level, " he said Neurons tend to regulate excitable cells just like other neurons or muscles with synapses But we were surprised to find that they formed synaptic structures with epithelial stem cells, which were not typical targets for neurons "The researchers then confirmed that nerves did target stem cells The sympathetic nervous system is usually activated at a constant low level to maintain a steady state of mind The researchers found that this low level of neural activity kept stem cells in a state of build-up for regeneration At prolonged low temperatures, the nerves are activated more often and release more neurotransmitters that cause stem cells to activate quickly to regenerate the hair follicles and grow new hair The researchers also looked at what maintained the neural link with hair follicle stem cells The loss of the neural connection between sympathetic nerve contraction sylithes and hair follicle stem cells when removing muscles connected to the hair follicles indicates that the muscles are the necessary structural support for connecting sympathetic nerves to hair follicles In addition to studying hair follicles in a fully formed state, researchers also studied how the system developed in the first place, where muscles and nerves initially reached the hair follicles "We found that the signal came from the developing follicles themselves, " said the study's lead author, a postdoctoral researcher in the lab It secretes a protein that regulates the formation of smooth muscles and then attracts sympathetic nerves By adulthood this interaction reverses the nerves and muscles together to regulate hair follicle stem cells to regenerate new hair follicles Then it shuts down the cycle - the developing hair follicles build their own ecological niche "Responding to environmental nerves is the signaling component of a neural transmitter that activates stem cells and the muscle is the structural component that connects nerve fibers directly to hair follicle stem cells "You can regulate hair follicle stem cells in many different ways and they are excellent models for studying tissue regeneration, " he said This particular response helps to combine tissue regeneration with external changes such as temperature It's a two-tiered response: chicken skins are a quick way to protect or relieve in the short term, but when the cold lasts, let the stem cells know it's time to regenerate new hairtor This becomes a good mechanism "In the future, researchers will further explore how the external environment affects stem cells in the skin in stable conditions in the body or in conditions such as healing of wounds