Akademik Veri Yönetim Sistemi
Journal of Neuroscience, cilt.35, sa.2, ss.853-863, 2015 (SCI-Expanded)
© 2015 the authors.In addition to innervating the cerebral cortex, basal forebrain cholinergic (BFc) neurons send a dense projection to the basolateral nucleus of the amygdala (BLA). In this study,weinvestigated the effect of near physiological acetylcholine release on BLA neurons using optogenetic tools and in vitro patch-clamp recordings. Adult transgenic mice expressing cre-recombinase under the choline acetyltransferase promoter were used to selectively transduce BFc neurons with channelrhodopsin-2 and a reporter through the injection of an adeno-associated virus. Light-induced stimulation of BFc axons produced different effects depending on the BLA cell type. In late-firing interneurons, BFc inputs elicited fast nicotinic EPSPs. In contrast, no response could be detected in fast-spiking interneurons. In principal BLA neurons, two different effects were elicited depending on their activity level. When principal BLA neurons were quiescent or made to fire at low rates by depolarizing current injection, light-induced activation of BF caxonselicitedmuscarinic IPSPs. In contrast, with stronger depolarizing currents, eliciting firingabove ~6–8Hz, these muscarinic IPSPs lost their efficacy because stimulation of BFc inputs prolonged current-evoked after depolarizations. All the effects observed in principalneuronsweredependentonmuscarinicreceptorstype1,engagingdifferent intra cellular mechanisms in a state-dependent manner. Overall, our results suggest that acetylcholine enhances the signal-to-noise ratio in principal BLA neurons. Moreover, the cholinergic engagement of after depolarization may contribute to the formation of stimulus associations during fear-conditioning tasks where the timing of conditioned and unconditioned stimuli is not optimal for the induction of synaptic plasticity.