Paraventricular thalamic nucleus: Role of orexin and opioids in ethanol intake

描述（由申请人提供）：酒精中毒，也称为酒精使用障碍，是一种慢性衰弱性疾病，其特征是过量摄入酒精以及社交和职业功能受损。虽然大多数对介导这种疾病的大脑机制的研究都研究了下丘脑或中脑边缘区域，但最近的证据将注意力集中在一个相对未被充分研究的区域，即丘脑室旁核（PVT），它提供了调节下丘脑稳态和调节情绪的边缘核之间的重要中继点。 利用导致自愿消耗药理学相关水平乙醇的间歇性访问模型，我计划测试总体假设，即乙醇饮用会刺激下丘脑神经肽食欲素（OX）在PVT中发挥作用，主要作用于食欲素2而不是食欲素1受体（而不是其受体上的黑色素浓缩激素），特别是在前亚区域而不是后亚区域，并且这种作用反过来又增加了食欲素的局部水平。阿片类脑啡肽（ENK）促进进一步的乙醇摄入。由于这一系列事件可能对促进酒精滥用至关重要，因此我在目标 1 中建议研究乙醇饮用后发生的神经化学事件，从下丘脑中的 OX 转录到前 PVT 中的 ENK 释放。在目标 2 中，我将检查这些神经化学变化的行为结果，测试在 PVT 中注射 OX 和 ENK 对乙醇饮酒和情绪行为的影响，以及这些行为因内源性肽水平升高而自然增加的可能性。在目标 3 中，我将研究 OX 与 ENK 连接的分子机制，并研究这对于促进乙醇饮用所必需的可能性。总的来说，通过使用原代神经元培养、原位杂​​交和行为评估测试等各种技术，这些研究应该提供有关相对较少研究的细胞核、PVT 及其与乙醇摄入的潜在主要参与的重要新信息。除了这项工作应该发表的出版物之外，这将使我能够整合分子、细胞和行为的发现，这项拨款提案的资助将为我提供必要的研究和职业发展培训，以实现作为一名科学家的独立。 我会另外采取 参加洛克菲勒大学和三机构合作网络的高级课程并参加研讨会和讲习班，同时参加国家协会会议。 我将接受我的赞助商莎拉博士的专家指导 莱博维茨以及我的顾问委员会，再加上洛克菲勒大学的丰富资源，将使我能够学习新的实验方法，并对我的研究问题获得新的视角。因此，在进行创新研究的过程中，我将获得成功过渡为独立研究科学家所需的技能，并为酒精研究领域做出重大贡献。

DESCRIPTION (provided by applicant): Alcoholism, also known as alcohol use disorder, is a chronic debilitating disorder characterized by excessive ingestion of alcohol and impairment in social and occupational functioning. While most investigations of brain mechanisms mediating this disorder have studied the hypothalamus or mesolimbic regions, recent evidence focuses attention on a relatively understudied area, the paraventricular nucleus of the thalamus (PVT), which provides an important relay point between the homeostasis-regulating hypothalamus and emotion-regulating limbic nuclei. Utilizing the intermittent access model that leads to voluntary consumption of ethanol at pharmacologically-relevant levels, I plan to test th overall hypothesis that ethanol drinking stimulates the hypothalamic neuropeptide orexin (OX) to act in the PVT, primarily at the orexin 2 rather than orexin 1 receptor (and rather than melanin-concentrating hormone at its receptor) and specifically in the anterior rather than posterior subregion, and that this action, in turn, increases local levels of the opioid enkephali (ENK) to promote further ethanol intake. With this sequence of events possibly being critically important in promoting disordered alcohol use, I propose, in Aim 1, to investigate the neurochemical events that occur following ethanol drinking, from OX transcription in the hypothalamus to ENK release in the anterior PVT. In Aim 2, I will examine the behavioral results of these neurochemical changes, testing the effects of OX and ENK injection in the PVT on ethanol drinking and emotional behaviors and the possibility that these behaviors are naturally increased by elevated endogenous peptide levels. In Aim 3, I will then look at molecular mechanisms of this OX-to-ENK connection and examine the possibility that this is necessary for promoting ethanol drinking. Collectively, by using techniques as varied as primary neuronal culture, in situ hybridization, and behavioral assessment tests, these studies should provide significant new information on a relatively understudied nucleus, the PVT, and its potentially major involvement in ethanol intake. In addition to the publications that should come out of this work, which will allow me to integrate molecular, cellular, and behavioral findins, the funding of this grant proposal will give me the necessary training in both researh and career development to attain independence as a scientist. I will additionally take part in advanced coursework and attend seminars and workshops at The Rockefeller University and through the Tri-Institutional Collaboration Network, while participating in national society meetings. I will receive expert mentorship from my sponsor, Dr. Sarah Leibowitz, as well as my advisory committee which, together with the abundant resources at The Rockefeller University, will allow me to learn new experimental methods and gain new perspectives on my research questions. Thus, in the process of conducting innovative new research, I will gain the skills necessary to successfully transition into a position as an independent research scientist and to make a significant contribution to the field of alcohol research.