Effect of phenol on conduction and synaptic transmission block.

The effect of phenol on nerve conduction and ganglionic synaptic transmission has been studied on sciatic nerve and on the VIIIth sympathetic ganglion of the frog. Ganglionic synaptic transmission block occurred at lower concentration than axonal conduction block. Both, conduction and synaptic transmission recovered in Ringer's solutions after 10 minutes. CaCl2 5.4 mM antagonized partially the axonal conduction block and EGTA in Ringer's solution without CaCl2 increased the effect of phenol on axonal conduction block on desheated sciatic nerve. Early in the experiments phenol had a weaker effect than procaine but at 10 minutes the effect of procaine became steady state and the effect of phenol continued to increase.