[Effects of stimulation of afferent fibers of the gastric branch of the vagus nerve after vagotomy and anemia of the brain]

Abstract

Changes in efferent discharges of the left major splanchnic nerve and in smooth muscles potentials of the gastric pylorus and small intestine during electrical stimulation of afferent fibers of gastric branch of the dorsal vagus trunk (20 Hz, 5-10 V, 1 ms, 10 min) were studied in acute experiments in control, vagotomized and spinal cats. In control animals, stimulation of the gastric branch induced a decrease in the firing rate of the splanchnic nerve and fast potentials of the stomach and an increase in the fast potential frequency of the intestine. In spinal and vagotomized cats, inhibition of discharges during gastric branch stimulation turned into facilitation, inhibitory responses of the stomach were abolished, and activating effects on the intestine remained though being less obvious in spinal than in vagotomized animals. Slow potential of smooth muscles changed in opposite manner as compared to fast potentials. The data obtained are discussed in the light of functional differences in effects of stimulation of spinal and supraspinal afferents of the internal organs.