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

项目摘要 酒精中毒，也被称为酒精使用障碍，是一种慢性衰弱性疾病，其特征是过量摄入酒精，损害社会和职业功能。虽然大多数关于介导这种疾病的脑机制的研究都研究了下丘脑或中脑边缘区，但最近的证据将注意力集中在一个相对研究不足的区域，丘脑室旁核（PVT），它在调节下丘脑的稳态神经元和调节边缘核的情绪神经元之间提供了一个重要的中继点。利用间歇性接触模型，导致自愿消费的乙醇在酒精相关的水平，我计划测试的整体假设，乙醇饮用刺激下丘脑神经肽食欲素（OX）在PVT中发挥作用，主要是在食欲素2，而不是食欲素1受体（而不是黑色素将激素集中在其受体上），特别是在前部而不是后部亚区，这种作用，反过来，增加阿片样脑啡肽（ENK）的局部水平，以促进进一步的乙醇摄入。由于这一系列事件可能在促进酒精使用障碍方面至关重要，我建议在目标1中研究饮酒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，我将研究这些神经化学变化的行为结果，测试在PVT中注射OX和ENK对乙醇饮用和情绪行为的影响，以及这些行为通过升高的内源性肽水平而自然增加的可能性。在目标3中，我将研究这种OX α与β ENK连接的分子机制，并研究这对促进乙醇饮用是必要的可能性。总的来说，通过使用不同的技术，如原代神经元培养，原位杂交和行为评估测试，这些研究应该提供重要的新信息，一个相对不足的核，PVT，其潜在的主要参与乙醇摄入量。除了应该从这项工作中产生的出版物，这将使我能够整合分子，细胞和行为研究结果，这项拨款提案的资金将为我提供必要的研究和职业发展培训，以实现作为科学家的独立性。我还将参加高级课程，并参加洛克菲勒大学的研讨会和讲习班，并通过三大机构合作网络，同时参加国家社会会议。Sarah Leibowitz博士以及我的咨询委员会，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，并获得对我的研究问题的新观点。因此，在进行创新的新研究的过程中，我将获得必要的技能，成功地过渡到作为一个独立的研究科学家的位置，并作出重大贡献的酒精研究领域。

PROJECT SUMMARY 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 homeostasis­regulating hypothalamus and emotion­regulating limbic nuclei. Utilizing the intermittent access model that leads to voluntary consumption of ethanol at pharmacologically­relevant levels, I plan to test the 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 melanin­concentrating 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 enkephalin (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 OX­to­ENK 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 findings, the funding of this grant proposal will give me the necessary training in both research 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 Tri­Institutional 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.