Habenula cholinergic neurons regulate anxiety during nicotine withdrawal via nicotinic acetylcholine receptors.
Ontology highlight
ABSTRACT: Cholinergic neurons in the medial habenula (MHb) modulate anxiety during nicotine withdrawal although the molecular neuroadaptation(s) within the MHb that induce affective behaviors during nicotine cessation is largely unknown. MHb cholinergic neurons are unique in that they robustly express neuronal nicotinic acetylcholine receptors (nAChRs), although their behavioral role as autoreceptors in these neurons has not been described. To test the hypothesis that nAChR signaling in MHb cholinergic neurons could modulate anxiety, we expressed novel "gain of function" nAChR subunits selectively in MHb cholinergic neurons of adult mice. Mice expressing these mutant nAChRs exhibited increased anxiety-like behavior that was alleviated by blockade with a nAChR antagonist. To test the hypothesis that anxiety induced by nicotine withdrawal may be mediated by increased MHb nicotinic receptor signaling, we infused nAChR subtype selective antagonists into the MHb of nicotine naïve and withdrawn mice. While antagonists had little effect on nicotine naïve mice, blocking ?4?2 or ?6?2, but not ?3?4 nAChRs in the MHb alleviated anxiety in mice undergoing nicotine withdrawal. Consistent with behavioral results, there was increased functional expression of nAChRs containing the ?6 subunit in MHb neurons that also expressed the ?4 subunit. Together, these data indicate that MHb cholinergic neurons regulate nicotine withdrawal-induced anxiety via increased signaling through nicotinic receptors containing the ?6 subunit and point toward nAChRs in MHb cholinergic neurons as molecular targets for smoking cessation therapeutics.
SUBMITTER: Pang X
PROVIDER: S-EPMC4982553 | biostudies-literature | 2016 Aug
REPOSITORIES: biostudies-literature
ACCESS DATA