ROLE OF INPUT FROM SAPHENOUS AFFERENTS IN ALTERED SPINAL PROCESSING OF NOXIOUS SIGNAL THAT FOLLOWS SCIATIC-NERVE CONSTRICTION IN RATS

An investigation was made into a possible contribution of saphenous ne rve to altered central processing of noxious information following sci atic nerve chronic constriction (CCI) in rats. Spinal sciatic neuron s pontaneous and noxious evoked activities were recorded in CCI rats, CC I rats with saphenous nerve sectioned just before the sciatic nerve co nstriction and sham operated rats. The results show (1) high values of spontaneous and noxious evoked activities with prolonged afterdischar ges in CCI rats with intact saphenous, (2) comparable high values of s pontaneous activity, but significantly reduced noxious evoked activity and afterdischarges in CCI rats with sectioned saphenous, (3) values in the normal range in the sham rats. Potential mechanisms underlying these results are discussed. (C) 1997 Elsevier Science Ireland Ltd.