Vanilloid receptor 1 (VR1), also designated capsaicin receptor, is a nonselective cation channel, structurally related to members of the TRP family of ion channels. The activation of TRPV1 leads to a painful, burning sensation. The sensitivity of TRPV1 to noxious stimuli, such as high temperatures, is not static. VR1 is expressed in primary sensory neurons and vagal nerves and activated VR1 induces the influx of cations, 2+ + particularly Ca and Na ions.Upon prolonged exposure to capsaicin, TRPV1 activity decreases, a phenomenon called desensitization. Desensitization of TRPV1 is thought to underlie the paradoxical analgesic effect of capsaicin.
