Cerebellar evoked potential elicited by stimulation of C-fiber in saphenous nerve of cat.

Stimulation of the saphenous nerve above C-fiber threshold strength evoked a field potential which consisted of an early component with latency of 11.8 +/- 3.5 ms and a late component with latency of 312.1 +/- 17.5 ms on the cerebellar cortex. After the A-fibers in saphenous nerve were blocked by the polarizing current selectivity, the stimulation at C-fiber suprathreshold elicited a C-fiber cerebellar evoked potential (C-CEP) with latency of 134.2 +/- 18.4 ms. C-CEP had the maximal amplitude on the vermian lobule VI of the contra- and ipsilateral cerebellar cortex and its phases reversed in the deep layer of this area. It was suggested that the selective C-fiber input could reach the cerebellar cortex and elicit a characteristic evoked potential. However, when A- and C-fiber inputs were elicited simultaneously, C-CEP might be inhibited by the A-fiber input.