Reflex control of the autonomic nervous system activity from the glucose sensors in the liver in normal and midpontine-transected animals

Abstract

Intraportal venous infusion of glucose resulted in a significant post-infusion decrease in the mean discharge rate in the adrenal nerve and the hepatic branch of the splanchnic nerve. Intraportal venous infusion of the same amount of glucose caused a significant increase in discharge rate of the pancreatic branch of the vagus nerve. After section of the hepatic branch of the vagus nerve, the same procedure induced no change in discharge rates in any of these nerves. Repetitive electrical stimulation of the central stump of the hepatic branch of the vagus nerve also caused reflex changes in efferent discharge rates in these three nerves, an increase in discharge rate in the hepatic branch of the splanchnic nerve and adrenal nerve, and a decrease in the pancreatic branch of the vagus nerve in the normal animals and also in midpontine-transected animals. The reflex network may consist of glucose-sensitive hepatic afferents, a reflex center in the hindbrain, and vagal pancreatic efferents, adrenal and splanchnic-hepatic efferents. This network contributes a neural regulatory mechanism to the control of blood glucose levels.