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

在依赖酒精的人中，压力在促使酒精过量消耗(Etoh)的复发中起着关键作用。即使在非依赖型人群中，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，在过量摄入乙醇中发挥作用。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乙醇相关行为中的作用的理解。为此，我们花了多年的时间来研究CRF系统的内源性配体urocortin-1(Ucn1)，它与原型配体CRF密切相关，但与两种CRF受体的亲和力比CRF本身更高。虽然酒精滥用和成瘾的领域通常集中在中脑边缘多巴胺途径和大脑结构，如腹侧被盖区和伏隔核，但我们的实验室提供了一系列证据，支持Edinger-Westphal核(EWCP)的中央投射神经元在乙醇摄取和敏感性中所起的作用。Ucn1在大脑中的主要表达部位在EWCP内，EWCP-Ucn1的表达与过量摄入乙醇的遗传易感性之间的关系已被确定。人们对EWCP作为参与乙醇摄入的大脑区域的进一步兴趣是基于观察到除了Ucn1外，可卡因和苯丙胺调节的转录物(CART)神经肽和Ghrelin受体(GHSR)在EWCP中都高度表达。有趣的是，这些蛋白质也与过量的乙醇消耗和乙醇诱导的奖励有关，我们假设EWCP在过度的乙醇消耗中的作用取决于Ucn1与CART、GHSR和其他蛋白质之间的相互作用。因此，本建议的特定目标1试图使用定量PCR阵列技术来阐明Ucn1与其他与Etoh相关行为相关的EWCP富含基因之间的相互作用，而我的建议的特定目标2试图利用慢病毒介导的RNA干扰来研究EWCP内Ucn1表达下调后酗酒和Etoh诱导的奖赏的行为模型。这些极具创新性的实验不仅将最终确定EWCP-Ucn1在两种相关的酒精中毒行为内表型中的重要性，还将使用定量基因表达分析来帮助解开EWCP在过量摄入乙醇中所起的复杂作用。

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.