Have you ever wondered why is it that scratching makes you feel better? Maybe you don’t have an answer for this question, but researchers from the University of Minnesota seem to have resolved the mystery.

 

The researchers focused their study on a kind of spinal nerve that transmits the “itch” signal to the brain. They sedated long-tailed macaques for the study and placed recording electrodes on their spinal nerves. They further injected a chemical into the skin of a leg to produce itching. In response, the nerves fired electrical signals.

 

Then, with the help of a hand-held metal device that simulates three monkey fingers the researchers scratched the leg and they found that the firing rate dropped, which means the monkey felt somewhat relieved.

 

On the other hand, the researchers used the device on a monkey that had not been injected with the “itchy” chemical and found that the scratch actually caused the firing rate to increase, which suggests that the nerves react much differently when there isn’t an itch to be scratched.

 

However, scratching may cause skin damage, the researchers said, hoping that they will be able to find revolutionary ways to stop the itch without “tearing” the skin.

 

“Although there is a long way to go, methods that can induce a pleasurable scratch sensation without damaging the skin, via mechanical stimuli or drugs that can inhibit these neurons, could be developed to treat chronic itch,” said Glenn J. Giesler, Jr., a neuroscientist at the University of Minnesota in Minneapolis, lead author of the study.