Synaptic potentials of hypoglossal motoneurons and their relation to reflex deglutition

Abstract

Intracellular recordings were made from hypoglossal motoneurons in decerebrate cats. Stimulation of the superior laryngeal nerve produced excitatory and inhibitory postsynaptic potentials, often a combination of both in the same motoneuron. These responses were polysynaptic and differed from one neuron. to another and varied widely depending upon the characteristics of the stimulation. A continuous repetition of the stimuli produced summation of the excitatory synaptic potentials leading to a short depolarization from which arose the spike discharge pattern associated with swallowing. The short depolarization was also present with the burst discharge of swallowing induced by a squirt of water into the oropharynx. It may be likely inferred that the behaviour of synaptic potentials of hypoglossal motoneurons will bear some functional relation to the pattern of the tongue movements during swallowing. © 1969, PHYSIOLOGICAL SOCIETY OF JAPAN. All rights reserved.