Excitation conduction in Auerbach's plexus of rabbit small intestine

Excitation conduction in Auerbach's plexus of the rabbit small intestine was investigated by analyzing its evoked potentials as the response to a single electrical stimulus given to this plexus. When the conduction distance was 1 mm, two spike waves were recorded. Conduction velocities of nerve impulses were 0.3-0.5 m/s, and chronaxie was 0.06-0.11 ms. When the distance between stimulating and recording electrodes was further increased, evoked potential waves became multiple and small, until beyond 15 mm in the longitudinal direction and beyond 3 mm in the circular direction they could no longer be recorded. Evoked potentials recorded at a distance greater than 2 mm were reduced in their amplitude, and some potential waves were abolished after repeated stimulation with high frequency above 50/s, and also after hexamethonium application and lack of oxygen. It was concluded that in Auerbach's plexus nerve impulses spread through multiple pathways, conducting mainly on the longitudinal axis of the small intestine, and that some impulses make synaptaic transmission at ganglia.