Clonazepam activates the transient receptor potential melastatin 8 (TRPM8) ion channel

Abstract

Benzodiazepines represent a major class of drugs prescribed as treatments for anxiety, insomnia and seizures. They act by engaging GABAA receptors in the central nervous system to depress neuronal excitability. Here, the polypharmacology of benzodiazepines was explored by studying their engagement of human TRP channels revealing clonazepam acts as a robust and selective activator of the TRPM8 ion channel. Clonazepam-evoked Ca2+ signals were observed in cells expressing human TRPM8 channels, and in mouse trigeminal neurons. These responses were completely blocked by pharmacological or genetic inhibition of TRPM8 function. This discovery likely explains why clonazepam is an effective treatment for the painful oral condition known as burning mouth disorder, where local activation of TRPM8 channels in sensory neurons mitigates the painful symptoms of this disease.