Responses to heat of C-fiber nociceptors in monkey are altered by injury in the receptive field but not by adjacent injury.
We sought to determine the effects of a cut injury on the thermal responsiveness of C-fiber nociceptors sensitive to heat and mechanical stimuli (CMHs). Teased fiber techniques were used to record from single CMHs that innervated the hairy skin of the monkey arm. Responses to heat stimuli ranging from 41 to 49 degrees C were compared before and after injury. In 11 CMHs, the injury was applied 4 mm peripheral to the edge of the receptive field. The response to the heat sequence was not significantly altered by this adjacent injury. In 16 CMHs, a cut was applied directly to the receptive field. This direct injury led to a significant increase in response to the sequence of heat stimuli (i.e., sensitization). It is concluded that spreading sensitization of C-fiber nociceptors to a cut injury does not occur in monkey.
Campbell
James N
JN
Department of Neurosurgery, School of Medicine, Johns Hopkins University, Baltimore, MD 21205 U.S.A. Applied Physics Laboratory, School of Medicine, Johns Hopkins University, Baltimore, MD 21205 U.S.A. Department of Anesthesiology and Critical Care Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD 21205 U.S.A.
Khan
Adil A
AA
Meyer
Richard A
RA
Raja
Srinivasa N
SN
D000818:Animals; D006358:Hot Temperature; D008252:Macaca fascicularis; D009412:Nerve Fibers / Q000502:physiology*; D009619:Nociceptors / Q000293:injuries* / Q000502:physiology; D010146:Pain / Q000209:etiology / Q000503:physiopathology; D010812:Physical Stimulation