Reexposure to nicotine during withdrawal increases the pacemaking activity of cholinergic habenular neurons

Item Type:	Article
Title:	Reexposure to nicotine during withdrawal increases the pacemaking activity of cholinergic habenular neurons
Creators Name:	Goerlich, A. and Antolin-Fontes, B. and Ables, J.L. and Frahm, S. and Slimak, M.A. and Dougherty, J.D. and Ibanez-Tallon, I.
Abstract:	The discovery of genetic variants in the cholinergic receptor nicotinic CHRNA5-CHRNA3-CHRNB4 gene cluster associated with heavy smoking and higher relapse risk has led to the identification of the midbrain habenula-interpeduncular axis as a critical relay circuit in the control of nicotine dependence. Although clear roles for {alpha}3, {beta}4, and {alpha}5 receptors in nicotine aversion and withdrawal have been established, the cellular and molecular mechanisms that participate in signaling nicotine use and contribute to relapse have not been identified. Here, using translating ribosome affinity purification (TRAP) profiling, electrophysiology, and behavior, we demonstrate that cholinergic neurons, but not peptidergic neurons, of the medial habenula (MHb) display spontaneous tonic firing of 2-10 Hz generated by hyperpolarization-activated cyclic nucleotide-gated (HCN) pacemaker channels and that infusion of the HCN pacemaker antagonist ZD7288 in the habenula precipitates somatic and affective signs of withdrawal. Further, we show that a strong, {alpha}3{beta}4-dependent increase in firing frequency is observed in these pacemaker neurons upon acute exposure to nicotine. No change in the basal or nicotine-induced firing was observed in cholinergic MHb neurons from mice chronically treated with nicotine. We observe, however, that, during withdrawal, reexposure to nicotine doubles the frequency of pacemaking activity in these neurons. These findings demonstrate that the pacemaking mechanism of cholinergic MHb neurons controls withdrawal, suggesting that the heightened nicotine sensitivity of these neurons during withdrawal may contribute to smoking relapse.
Keywords:	nAChRs, TRAP Profiling, Animals, Mice
Source:	Proceedings of the National Academy of Sciences of the United States of America
ISSN:	0027-8424
Publisher:	National Academy of Sciences
Volume:	110
Number:	42
Page Range:	17077-17082
Date:	15 October 2013
Official Publication:	https://doi.org/10.1073/pnas.1313103110
PubMed:	View item in PubMed

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