A person will go crazy because the pigment melanin, which colors the hair, stops being produced. It is produced by special cells called melanocytes. They are located at the base of the hair. Then melanin is transferred to the cells of the growing hair – keratinocytes. And it stops being produced for several interrelated reasons. With age, the enzymes that break down hydrogen peroxide H2O2 in melanocytes begin to work worse (the exact reason is not known). Accumulating in large quantities, hydrogen peroxide damages the enzyme tyrosinase, which is responsible for the synthesis of melanin. In addition, other proteins are damaged. For example, the proteins responsible for the transfer of melanin from melanocytes to keratinocytes stop working. A very important protein, Bcl2, which protects melanocytes from apoptosis – programmed death – stops working. Melanocytes gradually die, and the stem cells from which they are formed, divide more slowly with age and do not replenish their losses. When melanin stops being produced, hair turns white. Its structure changes. Interestingly, gray hair cells often divide faster, especially in the hair core. Hair grows faster, its core becomes less dense, voids and air bubbles form in it. Light “mouths” in these voids diverge in different directions and because of this, hair appears white (for the same reason, foam consisting of transparent water appears white. Although the amount of hydrogen peroxide can increase under stress, it cannot spread along the entire perimeter). hair length and bleach it – after all, living cells, where it is formed, exist only at the base of the hair. That is why you cannot go gray in 5 minutes. And yet, cases of rapid “graying” have been recorded by scientists and doctors. How does it happen that you can quickly go gray due to a special form of baldness, often associated with severe stress – diffuse hair loss. Sometimes most of the dyed hair falls out, but the gray hair remains (why is unknown). A case of this rare form of baldness without prior stress has been described. There are also cases where after diffuse baldness hair grows back to normal thickness. In one case it was completely grey, and in another – colored. But in all the scientifically described cases that I was able to find, the person did not go grey in 5 minutes, but in a few days or weeks.
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