Heat Sensitivity Linked to Pigmentation
The same skin cells that produce the pigment melanin also release a signaling chemical that can change how the cells respond to heat and touch.
Researchers have identified a mechanism that links a person's pigmentation to his or her sensitivity to heat and touch.
According to a research paper published in Scientific Reports, the link has to do with the chemical dopamine, which plays important signaling roles throughout the body. In the skin, dopamine is produced by cells called melanocytes, which also produce the pigment melanin that determines skin color. Dopamine can cause an increased expression of a specific gene called TRPV1, and a decreased expression of gene Piezo2. The two genes are known links to the heat and mechanical sensitivity of the skin, meaning increased dopamine could lead to increased heat sensitivity, but decreased pressure sensitivity.
In a press release, co-author Yi Ye said the mechanism could have developed as an additional way to protect the skin of people who live in environments with intense sun. While melanin helps protect the skin from UV damage, the heightened heat sensitivity caused by dopamine could also warn people away from excessive sun exposure.
In the future, the research may also help health care professionals better understand the differences in pain perceptions across individuals.