title: Effects of stimulation of Auerbach's plexus on both longitudinal and circular muscles.
abstract: The effects of repetitive electrical stimulation of a node of Auerbach's plexus on both longitudinal and circular muscles were investigated by simultaneous recording of both muscle contractions. L-formed muscle strips, longitudinal and circular muscle strips, were made from a segment of rabbit small intestine. One strip was cut along, another strip was cut at 90 degrees to the oral-anal axis. The longitudinal muscle strip was peeled and Auerbach's plexus was exposed. Under a stereodissecting microscope the stimulating electrode, with tip diameter of 5--10 micron, was placed on a node of Auerbach's plexus situated at the junction of both muscle strips. Repetitive electrical stimulation of a node produced a mainly excitatory effect on spontaneous contractions of an orally-directed longitudinal muscle strip, excitatory and inhibitory effects on an anally-directed longitudinal muscle strip and a mostly excitatory effect on a circular muscle strip which always appeared with a delay after that on the longitudinal muscle. In a few instances the inhibitory effect of nodal stimulation was observed on the circular muscle. The evoked excitatory effect of longitudinal muscle was mainly due to a cholinergic mechanism, while that of circular muscle was partially due to cholinergic and partially noncholinergic activity. The evoked inhibition was nonadrenergic.
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D004558:Electric Stimulation; D005260:Female; D006584:Hexamethonium Compounds / Q000494:pharmacology; D066298:In Vitro Techniques; D007421:Intestine, Small; D008297:Male; D008839:Microelectrodes; D009119:Muscle Contraction / Q000187:drug effects; D009197:Myenteric Plexus / Q000502:physiology*; D011817:Rabbits; D013779:Tetrodotoxin / Q000494:pharmacology
chemical_list: D006584:Hexamethonium Compounds; D013779:Tetrodotoxin; D001285:Atropine; D000109:Acetylcholine