[Effects of the insular cortex stimulation upon realization of the antro-fundal gastric reflex in alert dogs].

Abstract

Neuroanatomic studies demonstrate direct descending projections from the insular cortex to the gastric area of the solitary tract nucleus. This allows us to hypothesize that the insular cortex is able to modulate vago-vagal gastric motor reflexes such as antro-fundal inhibitory reflex. In experiments on conscious dogs demonstrating fasting gastric motility, the effects of electrical stimulation of the insular cortex upon realization of the gastric antro-fundal reflex were studied. Distension of the antrum applied during active period of gastric motility inhibited contractions of the fundus. Electrical stimulation of the insular cortex did not affect the time pattern of fasting gastric motility but resulted in significant prolongation of the antro-fundal reflex. Thus, activation of the insular cortex leads to augmentation of gastric vago-vagal inhibitory reflex. The effect may be realized due to corticofugal modulation ofvago-vagal neurotransmission within the nucleus of the solitary tract.