Journal of neurophysiology
-
1. Properties of sensory receptors with slowly conducting nerve fibers (less than 10 m/s) were studied using a rat skin-saphenous nerve in vitro preparation where receptive fields of identified single units can be isolated and superfused at the corium side with defined chemical solutions. 2. With mechanical search stimuli, 150 slowly adapting units were identified, 88% C-fibers, and the remainder, A delta-fibers. ⋯ In some experiments the calcium concentration in the superfusate of receptive fields was lowered to 0.3 mM, which induced ongoing activity in C-fibers and markedly increased the BK responses in two polymodal units tested. Increasing the calcium concentration to 3.0 mM reversed these effects. 10. After completing the BK test protocol, polymodal C-fibers were exposed to other chemicals.(ABSTRACT TRUNCATED AT 400 WORDS)