Touch-neuron TRPV4 acts as the brain’s stop-scratching brake

A new study shows TRPV4 ion channels in touch-sensitive neurons act as a negative feedback brake that tells the brain when scratching has achieved relief, regulating the duration of itch. In mice, removing neuronal TRPV4 reduces scratching frequency but extends each bout, suggesting skin TRPV4 triggers itch while neuronal TRPV4 restrains it. This finding implies future therapies should target TRPV4 more precisely to treat chronic itch without blunting the brain’s stop signal.