Muscarinic receptors mediate the effect of acetylcholine (ACh) on neurons of the bed nucleus of the stria terminalis (BNST).

This study was designed to determine the type of receptor mediating the effect of ACh on BNST neurons. 45% of BNST neurons showed a dose-dependent monophasic increase in firing rate in response to ACh. Muscarinic antagonist blocked the effects of ACh. Amygdala stimulation (Amyg S) elicited excitatory responses, but atropine and hexamethonium had no effect on the Amyg S induced excitation. The experiment shows that the excitatory effect of ACh on BNST neurons is mediated by muscarinic receptors, while the excitatory effects of Amyg S on BNST neurons is not mediated by ACh.