Ketamine Inhibits Presynaptic and Postsynaptic Nicotinic Excitation of Identified Cardiac Parasympathetic Neurons in Nucleus Ambiguus

Abstract

Ketamine inhibits the presynaptic nicotinic receptors responsible for facilitating neurotransmitter release, as well as the direct ligand-gated inward current, but does not alter the nicotinic augmentation of non-N-methyl-D-aspartate currents in brainstem parasympathetic cardiac neurons. Such actions may mediate the decrease in parasympathetic cardiac activity and increase in heart rate that occurs with ketamine.