Transient receptor potential melastatin 8 (TRPM8)

Transient receptor potential melastatin 8, or TRPM8, is an ion channel on sensory nerves that opens in response to cool temperatures and to menthol, producing the sensation of cold.

The channel activates as skin temperature drops below roughly room temperature and is the main reason the body can sense a cool breeze or a cold drink. Menthol, eucalyptol and synthetic cooling agents open it chemically, which is why mint feels cold even at body temperature. TRPM8 is found on a subset of small sensory neurons distinct from those carrying the heat sensor TRPV1, and it is also expressed in the prostate, bladder and cornea, where its function is less clear.

TRPM8 comes up in research on cold allodynia, the painful sensitivity to cold that follows nerve injury and some chemotherapy, and on dry eye. CBD and several other cannabinoids have been reported to block TRPM8 in laboratory experiments, which is one of the more consistent findings among the TRP channels; what this means for sensation in people has not been determined.