Edinger-Westphal Urocortin-1 Involvement in Binge Ethanol Intake and Reward

压力在酒精依赖者过度饮酒（EtOH）的复发中起着关键作用。即使在非依赖人群中，也有证据支持神经应激网络（如促肾上腺皮质激素释放因子（CRF）系统）在过量乙醇摄入中的作用。不幸的是，CRF系统复杂的神经解剖学和药理学特征阻碍了我们对其特定成分在EtOH相关行为中的作用的理解。为此，我们已经投入了多年的研究，以检查尿皮质素-1（Ucn 1），CRF系统的内源性配体，其与原型配体CRF密切相关，但与CRF受体结合的亲和力高于CRF本身。虽然酒精滥用和成瘾的领域通常集中在中脑边缘多巴胺通路和大脑结构，如腹侧被盖区和延髓核，但我们的实验室提供了会聚的证据来支持Edinger-Westphal核（EWcp）的中央投射神经元在EtOH摄入和敏感性中的作用。Ucn 1在大脑中表达的主要位点是在EWcp内，并且已经确定了EWcp-Ucn 1表达与过量EtOH摄入的遗传易感性之间的关系。对EWcp作为参与EtOH摄入的大脑区域的进一步兴趣是基于这样的观察：除了Ucn 1之外，可卡因和安非他明调节转录物（CART）神经肽以及饥饿素受体（Ghsr）都在EWcp内高度表达。有趣的是，这些蛋白质也涉及过量的EtOH消耗和EtOH诱导的奖励，我们假设EWcp在过量EtOH消耗中的作用取决于Ucn 1和CART，Ghsr和其他蛋白质之间的相互作用。因此，本提案的具体目标1旨在使用定量PCR阵列技术阐明Ucn 1与其他与EtOH相关行为相关的EWcp富集基因之间的相互作用，而我的提案的具体目标2旨在使用慢病毒介导的RNA干扰，在EWcp内敲低Ucn 1表达后，检查EtOH暴饮和EtOH诱导的奖励的良好表征的行为模型。这些高度创新的实验不仅将最终确定EWcp-Ucn 1在两种相关的行为内表型酒精中毒中的重要性，而且还将使用定量基因表达分析来帮助解开EWcp在过量EtOH摄入中发挥的复杂作用。

Stress plays a key role in precipitating relapse to excessive ethanol (EtOH) consumption in dependent alcoholics. Even in non-dependent populations, evidence supports a role for neural stress networks, such as the corticotropin-releasing factor (CRF) system, in excessive EtOH intake. Unfortunately, the complex neuroanatomical and pharmacological features of the CRF system have hindered our understanding of the roles of its specific components in EtOH-related behaviors. To this end, we have devoted years of study to the examination of Urocortin-1 (Ucn1), an endogenous ligand of the CRF system that is closely related to the prototypical ligand CRF, yet binds to both CRF receptors with higher affinity than CRF itself. While the fields of alcohol abuse and addiction have typically focused on the mesolimbic dopamine pathway and brain structures such as the ventral tegmental area and nucleus accumbens, our laboratory has provided converging lines of evidence to support a role for the centrally-projecting neurons of the Edinger-Westphal nucleus (EWcp) in EtOH intake and sensitivity. The primary site of Ucn1 expression in the brain is within the EWcp, and a relationship between EWcp-Ucn1 expression and a genetic predisposition to excessive EtOH intake has been identified. Further interest in the EWcp as a brain region involved in EtOH intake is based on the observation that in addition to Ucn1, the cocaine- and amphetamine-regulated transcript (CART) neuropeptide, and the ghrelin receptor (Ghsr) are both highly expressed within EWcp. Intriguingly, these proteins have also been implicated in excessive EtOH consumption and EtOH-induced reward, and we have hypothesized that the role of the EWcp in excessive EtOH consumption is dependent on the interactions between Ucn1 and CART, Ghsr, and additional proteins. Thus, Specific Aim 1 of this proposal seeks to use quantitative PCR array technology elucidate interactions between Ucn1 and other EWcp-enriched genes that are relevant for EtOH-related behaviors, and Specific Aim 2 of my proposal seeks to examine well-characterized behavioral models of EtOH binge-drinking and EtOH- induced reward following knockdown of Ucn1 expression within the EWcp, using lentiviral-mediated RNA interference. These highly innovative experiments will not only conclusively determine the importance of EWcp-Ucn1 in two relevant behavioral endophenotypes of alcoholism, but will also use quantitative gene expression analyses to aid in unraveling the complex role that the EWcp plays in excessive EtOH intake.