Electrophysiological study on the vagal innervation of the adrenal gland in the rat.

Action potentials evoked by stimulation of the ventral or dorsal subdiaphragmatic vagal nerve trunks were recorded from the adrenal branch of the splanchnic nerve in the urethane-anesthetized rat. Action potentials were clearly demonstrated after averaging over 50 times by a computer. In some experiments action potentials evoked by stimulation of the adrenal branch of the splanchnic nerve were observed in the celiac branch of the vagus nerve. The observations indicate the existence of a nervous pathway from the ventral and dorsal subdiaphragmatic vagus nerve to the adrenal gland, and the conduction velocities (0.32-0.91 m/s) suggest that the majority of the nerve fibers belong to the non-myelinated C-fiber group.