The more you scratch you, the more it will sting you. This truth repeated by mothers throughout history has been confirmed by a study of the School of Medicine in St. Louis (USA), indicating that scratching causes the brain to release serotonin, which intensifies the itch.
For the study, published in the journal Neuron, serotonin production in a group of mice that were injected with a substance that causes itchy skin are blocked. Comparing their reactions with other unmodified mice, rodents found that serotonin produced not scratched less.
"Scratching may relieve itching by creating a small pain in the skin. The body responds to pain by releasing serotonin, which increases the feeling of itching, "says senior researcher Zhou-Feng Chen, PhD, director of the University Center for the Study of Itch Washington.
While preventing the mouse secrete serotonin makes you less sensitive to itching, the researcher does not consider blocking this substance is the key to relieve itching in humans. "Serotonin is involved in growth, bone metabolism and mood regulation, and eliminate lock the natural way to control the pain."
Block receptors for chronic itching
The nerve cells of the spinal cord are responsible GRPR to transmit itch sensation from the skin to the brain. For Chen, a way to treat chronic itching could be "block communication between serotonin and GRPR cells. To do this we isolated the 5HT1A receptor, serotonin used by brain cells to activate. "
The researchers blocked the 5HT1A receptor from a group of mice was injected with the same substance that causes itching. The result was that these mice were scraped less.
According to researchers, this study provides some clues to break the ´vicious circle´ of itching and scratching, especially in people who experience chronic itching. But until the investigation proceeds, Chen advised to "heed the advice of mothers."