Inhibition of cardiac sympathetic nerve activity during swallowing evoked by laryngeal afferent stimulation in the cat.

Spontaneous swallowing or the buccopharyngeal phase of swallowing evoked by electrical stimulation of the superior laryngeal nerve was accompanied by a pronounced decrease of sympathetic activity in the cardiac nerve. This reduction of sympathetic activity was not related to other influences such as postinspiratory inhibition or baroreceptor-mediated inhibition. Intracellular recordings from sympathetic preganglionic neurones revealed hyperpolarization during the buccopharyngeal phase of swallowing, possibly due to postsynaptic inhibition.