TRP IN FEELING THE COLD
One of transient receptor
potential (TRP) ion channels, TRPM8 is sensitive to reduction in ambient
temperature: in response to cold TRPM8 depolarizes afferent nerve fibres in the
somatosensory system, which induces psychophysical sensations of cold.
TRP ion channels are a
family of channels expressed in many cells throughout the body, they allow the
influx of calcium ions into cells. Little is known about their physiological
function.
Chuang et al. (The super-cooling
agent icilin reveals a mechanism of coincidence detection by
temperature-sensitive TRP channel. Neuron 43, 859-869, 2004.) show that for some TRP
channels (TRPM8) to be maximally effective two or more stimuli must be present
at the same time, indicating that they function as coincidence detectors.