PSYC 4750 Lecture Notes - Group C Nerve Fiber, Trpv1, Thermoreceptor
5 Feb 2013
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Document Summary
Nonpainful temperature sensations originate from receptors in the skin and they depend on the neocortex for their conscious appreciation. Thermoreceptors are neurons that are exquisitely sensitive to temperature. Temperature- sensitive neurons clustered in the hypothalamus and the spinal cord are important in maintaining stable body temperature. Thermoreceptors in the skin contribute to our perception of temperature. Temperature sensitivity is not spread uniformly across the skin. Some spots about 1 mm wide are especially sensitive to either hot or cold, but not both. The fact that the locations of hot and cold sensitivity are different demonstrates that separate receptors encode them. The sensitivity of a sensory neuron to a change in temperature depends on the type of ion channels the neuron expresses. Receptors responding to temperatures above 43 c are hot" receptor proteins called trpv1. Cold" receptor are trpm8 and are activated by nonpainful decreases in temperature below 25 c.
