Scientists discover the brain’s hidden “stop scratching” switch

Science Daily Scientists have uncovered a hidden “stop-scratching” signal in the nervous system that tells your brain when enough scratching is enough. The discovery centers on a molecule called TRPV4, which acts like part of an internal braking system for itch relief. In experiments involving chronic itch similar to eczema, mice missing this signal scratched less often—but when they did scratch, they couldn’t stop. When an itch strikes, scratching usually brings relief after a few moments. Scientists have now uncovered part of the biological system that tells the brain when enough scratching has occurred. The discovery reveals how the nervous system naturally limits scratching and may help explain why this process breaks down in people with chronic itch disorders. The findings were presented at the 70th Biophysical Society Annual Meeting.