TRPM8 (Transient Receptor Potential Melastatin 8) is an ion channel predominantly involved in sensing cold temperatures and cooling agents like menthol. Belonging to the TRP (Transient Receptor Potential) family of ion channels, TRPM8 is expressed in sensory neurons and various tissues, including the skin, prostate, and bladder. This channel is activated by temperatures below approximately 26°C (78.8°F) and by chemical stimuli such as menthol and icilin.

Upon activation, TRPM8 allows the influx of calcium (Ca²⁺) and sodium (Na⁺) ions into the cell, leading to depolarization of the neuronal membrane and the generation of action potentials. These signals are then transmitted to the brain, where they are perceived as a sensation of cold. This mechanism plays a crucial role in thermoregulation and the sensory perception of temperature changes.

In addition to its role in cold sensation, TRPM8 has been implicated in various physiological and pathological processes. It is involved in the regulation of bladder function, and its expression levels have been linked to certain cancers, particularly prostate cancer, making it a potential therapeutic target. Research on TRPM8 continues to uncover its diverse functions and potential applications in medicine, including pain management, cancer treatment, and the development of cooling agents for therapeutic use.