Not all itching goes away if you scratch yourself. 15% of people suffer from long-term itching , sometimes caused by various diseases and medications. Scientists at the National Institute for Dental and Craniofacial Research in Bethesda (Maryland, USA) have discovered that there is a molecule that sends itch signals to neurons in the spinal cord, which in turn transmit them to the brain. This could lead to a definitive remedy for chronic itching .
Through a series of experiments, the authors of the research detected that the sensation of itching or pruritus only begins if the so-called natriuretic polypeptide (NPPB) intervenes , regardless of what causes the itching. Working with mice deficient in NPPB, they found that when they were exposed to various substances that usually induce itching, nothing happened: the mice stopped scratching. They then identified the receptor for NPPB molecules, the NPRA protein, and removed it from the spinal cord, verifying that this measure had no impact on other sensory sensations, such as temperature, pain and touch. Therefore, the connection would form a biocircuit that specifically transmits the sensation of itchiness. "The work shows that itching, once considered a low-level form of pain, is a different sensation ," the authors conclude in the journal Science .
It remains to be confirmed whether blocking NPPB, which is also used in the heart, kidneys, and other parts of the body, can cause unwanted side effects.
