Afferent Nerve Fiber Activity Responding to Temperature Changes of the Scrotal Skin of the Rat.

摘要

The discharge pattern of rat scrotal afferents was studied during temperature changes of the skin. Of 49 afferents, 75 percent were both mechanosensitive and temperature sensitive while 25 percent responded only to temperature changes. The most frequent response to temperature change was a dynamic and static increase in discharge on cooling. However, among mechanosensitive and thermosensitive units which showed a dynamic cold discharge some units had no static discharge, some had a static warm discharge, and others had a minimal static discharge at an intermediate temperature. Bursting in the cold was common in both specific and mechanosensitive temperature receptors. The response properties to changing scrotal temperature of the second order afferents in the spinal cord, reported by Hellon and Misra (J. Physiol. 232:375, 1973), can be explained on the basis of a greater variety of peripheral thermosensitive afferent properties than was previously appreciated, and not by information processing at the first synapse. (Author)