Journal of neurophysiology
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1. The response of C polymodal nociceptors to thermal and mechanical stimuli applied to the monkey's face was recorded extracellulary in the trigeminal ganglion in rhesus monkeys anesthetized with sodium pentobarbital. Conduction velocities, determined from electrical stimulation of receptive fields (RFs), were in the range for unmyelinated C fibers (mean=0.82 m/s, n=20; SD=+/-0.17). ⋯ Depressed responses were sometimes produced by application of intense (greater than or equal 55 degrees C) stimuli, presumably as a result of partial inactivation of the receptor. 5. In a correlative analysis, the latency and pattern of discharge in a sample of units were compared with escape responses in two monkeys to temperature shifts into the noxious heat range (49 and 51 degrees C). The analysis revealed that the discharge of C polymodal nociceptors alone cannot account for fast escape responses, but the discharge may contribute to escape responses which occur more than 3.5 s after the onset of stimulation.