Reflex Inhibition of Bile Flow and Intestinal Motility Mediated Through Decentralized Celiac Plexus

Abstract

The celiac ganglia are anatomically and functionally related to the splanchnic nerves. The peripheral links in splanchnic efferent conduction pathways are made up of celiac ganglion cells. Splanchnic nerve components, however, are not the only nerve fibers which terminate in the celiac ganglia. In a recent experimental anatomical study, terminal branches of axons have been demonstrated in preparations of the celiac ganglia of the cat in which all the splanchnic nerve fibers which enter these ganglia had undergone degeneration, following bilateral section of the splanchnic nerves. Intact nerve fibers also have been demonstrated in sections of the distal segments of divided mesenteric nerves arising from the celiac plexus, after the fibers separated from their cells of origin had undergone degeneration. 1 These findings support the assumption that axons of enteric origin enter the celiac ganglia. If such fibers effect synaptic contacts with celiac ganglion cells, they might constitute the afferent limbs of reflex arcs with central connections in the celiac ganglia. The present investigation has been undertaken to test the hypothesis that reflex reactions can be mediated through the celiac plexus in the absence of intact nerve fiber connections with the central nervous system.

Methods. The experiments have been carried out on cats under nembutal anesthesia. The splanchnic and vagus nerves were divided bilaterally and the intestine transected in the lower portion of the jejunum. In one series of experiments, the common bile duct was cannulated and the drops of bile recorded. After the rate of flow was established, mesenteric nerves were stimulated either by means of a faradic current or distention of the ileum and colon. In another series, a balloon was placed in the proximal segment of the intestine and a kymographic record taken of the intestinal motility.