Excitation conduction in Meissner's plexus of rabbit small intestine.

Abstract

Excitation conduction in Meissner's plexus of the rabit small intestine was investigated by analyzing the records of potentials evoked by a single electrical stimulus applied to this plexus. Experiments were performed on the Meissner's plexus that remained attached to the circular muscle after the longitudinal muscle and mucous membrane were removed from intestinal segment. Conduction velocities of nerve impulses were 0.3-0.7 m/s, chronaxie of the nerve bundle was 0.06-0.12 ms. While the distance between the stimulating and recording electrodes was increased, the latency of evoked potentials was prolonged, the number increased, and the amplitude decreased; no potentials could be recorded when the distance was more than 4 mm. Evoked potentials recorded at relatively long conduction distance were reduced in amplitude or abolished after a repeated stimulation with high frequencies above 50/s, after hexamethonium application, and in a state of lack of oxygen. It was concluded that, in Meissner's plexus, nerve impulses spread through multiple pathways and make synaptic transmission at a relatively short conduction distance.