Department of Psychology & Neuroscience, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
Bowles Center for Alcohol Studies, University of North Carolina School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
Eur J Neurosci. 2018 Dec;48(11):3335-3343. doi: 10.1111/ejn.14222. Epub 2018 Nov 15.
Corticotropin-releasing factor (CRF) circuitry is a key component in plasticity underlying the transition to ethanol (EtOH) dependence. We have previously shown that chemogenetic silencing of CRF neurons stemming from the dorsolateral bed nucleus of the stria terminalis (dlBNST) and projecting to the ventral tegmental area (VTA) significantly blunts binge-like EtOH consumption. While CRF neurons in the BNST are thought to entail primarily a GABA phenotype, glutamatergic neurons within the BNST also innervate the VTA and influence consummatory behaviors. Here, we combined the well-validated Vgat-ires-Cre transgenic mice with chemogenetic tools to extend our previous findings and corroborate the contribution of the VTA-projecting dlBNST GABAergic circuitry in modulating binge-like EtOH consumption using "drinking-in-the-dark" procedures. Mice were given bilateral injection of Gi-coupled chemogenetic viral vector (or control virus) into the dlBNST and bilateral cannulae into the VTA. On test day, clozapine-N-oxide (CNO; or vehicle) was infused directly into the VTA to silence VTA-projecting dlBNST neurons and subsequent binge-like EtOH consumption was assessed. We then used immunohistochemistry (IHC) to determine the co-expression of CRF and viral vector. Our results showed that relative to vehicle treatment or CNO treatment in mice expressing the control virus, silencing VTA-projecting dlBNST GABAergic neurons by CNO treatment in mice expressing Gi-coupled chemogenetic virus significantly reduced binge-like EtOH intake. This effect was not seen with sucrose consumption. Our IHC results confirm a population of CRF-expressing GABAergic neurons within the dlBNST. This study directly establishes that VTA-projecting GABAergic neurons of the dlBNST modulate binge-like EtOH consumption.
促肾上腺皮质释放因子（CRF）回路是向乙醇（EtOH）依赖过渡的基础可塑性的关键组成部分。我们之前已经表明，来自终纹床核外侧部（dlBNST）并投射到腹侧被盖区（VTA）的 CRF 神经元的化学遗传沉默显著削弱了 binge-like EtOH 消耗。虽然 BNST 中的 CRF 神经元被认为主要具有 GABA 表型，但 BNST 中的谷氨酸能神经元也支配 VTA 并影响摄食行为。在这里，我们将经过充分验证的 Vgat-ires-Cre 转基因小鼠与化学遗传工具相结合，以扩展我们之前的发现，并使用“暗饮”程序证实调节 binge-like EtOH 消耗的 dlBNST 投射 GABA 能回路的贡献。将 Gi 偶联的化学遗传病毒载体（或对照病毒）双侧注射到 dlBNST 中，并将双侧套管插入 VTA 中。在测试日，将氯氮平-N-氧化物（CNO；或载体）直接输注到 VTA 中以沉默 VTA 投射 dlBNST 神经元，并随后评估 binge-like EtOH 消耗。然后，我们使用免疫组织化学（IHC）来确定 CRF 和病毒载体的共表达。我们的结果表明，与表达对照病毒的小鼠中的载体处理或 CNO 处理相比，在表达 Gi 偶联化学遗传病毒的小鼠中，CNO 处理沉默 VTA 投射 dlBNST GABA 能神经元显著减少了 binge-like EtOH 摄入。这一效应在蔗糖消耗中没有出现。我们的 IHC 结果证实了 dlBNST 中存在表达 CRF 的 GABA 能神经元群。这项研究直接证实了 dlBNST 投射到 VTA 的 GABA 能神经元调节 binge-like EtOH 消耗。
