Microneurographic identification of spontaneous activity in C-nociceptors in neuropathic pain states in humans and rats

摘要: C-nociceptors do not normally fire action potentials unless challenged by adequate noxious stimuli. However, in pathological states nociceptors may become hyperexcitable and generate spontaneous ectopic discharges. The aim of this study was to compare rat neuropathic pain models assess their suitability model the C-nociceptor activity found patients. Studies were performed normal rats (n=40), healthy human subjects (n=15), peripheral patients (n=20), five models: nerve crush (n=24), suture (n=14), chronic constriction injury (n=12), STZ-induced diabetic neuropathy (n=56), ddC-induced (n=15). Microneurographic recordings combined with electrical stimulation monitor multiple C fibers. Stimulation at 0.25 Hz allowed impulses be identified fluctuations baseline latency. Abnormal latency could produced several mechanisms, most reliably presence unexplained increases corresponding two or more additional potentials. Spontaneous present a proportion mechano-insensitive all models. three focal traumatic provided highest (59.5%), whereas polyneuropathy had fewer (18.6%), an intermediate (33.3%). Spontaneously active mechano-sensitive recorded. diseased useful for both short- long-term drug studies, animals humans.