Relapse to drug-seeking behavior is regulated by medial habenula NR4A2 in male and female mice

项目总结/摘要 物质使用障碍是复杂的终身复发的风险。复发脆弱性部分是编程的 在药物使用过程中，当药物滥用在奖赏回路中的作用使异常的 强背景/奖励记忆。这些记忆过程是常见的复发触发因素的基础， 与药物相关的线索或环境，并且可以非常持久。这种持续性可能归因于 表观遗传学（即通过改变染色质结构而发生的基因表达的调节， DNA序列本身的根本变化），这已被证明可以在细胞中建立稳定的变化。 功能，进而改变行为结果。这项建议的重点是审查分子和 可能参与恢复的细胞机制。最近的研究已经开始暗示MHb在 可卡因相关行为，但MHb在调节可卡因自我给药恢复中的作用 仍然是未知的。最近的实验室工作已经确定了组蛋白去乙酰化酶3（HDAC 3;一种强大的 基因表达的表观遗传调节因子）靶基因，Nr 4a 2，作为可卡因相关的重要调节因子， 行为NR 4A 2是一种转录因子，在发育过程中调节多巴胺信号传导的各个方面， 在MHb中密集表达。我将测试中心假设，即MHb调节恢复 可卡因以NR 4A 2依赖性方式自我给药。具体来说，我将研究Nr 4a 2的作用， 使用病毒表达的CCR 2C，一种依赖MHb的可卡因自我给药恢复， 内源性存在的NR 4A 2显性负剪接变体或野生型NR 4A 2来双向调节 NR 4A 2功能。我的初步数据显示，BCR 2C动物的恢复率降低， MHb中的NR 4A 2作为恢复行为的关键调节因子。为了更深入地了解 MHb对可卡因寻求行为以及自我给药、消退训练和戒断的反应， 我将使用单核RNA测序来寻找细胞类型比例、基因表达和基因表达的变化。 网络.在这些分析中，我还将寻找NR 4A 2依赖性变化和性别依赖性变化。 完成拟议的研究将大大提高我们对MHb恢复的理解， 并提供重要的洞察NR 4A 2和NR 4A 2依赖的基因调控。该培训奖学金将 让我发展分子和生物信息学的专业知识。在伍德博士和斯瓦鲁普博士的指导下 以及UCI的研究和专业发展环境，该奖学金将为以下方面提供基础： 一个成功的职业生涯作为一个独立的研究人员，专注于了解分子机制， 学习和记忆，导致吸毒行为复发。

Project Summary/Abstract Substance use disorder is complicated by a lifelong risk of relapse. Relapse vulnerability is programed partly during drug use, when the action of drugs of abuse in the reward circuit enables the formation of abnormally strong context/reward memories. These memory processes underlie common relapse triggers such as exposure to drug-associated cues or environments and can be extremely long lasting. This persistence may be attributed to epigenetics (i.e. modulation of gene expression that occurs through altered chromatin structure without fundamental changes to the DNA sequence itself), which has been shown to establish stable changes in cell function, and in turn changes in behavioral outcomes. This proposal is focused on examining the molecular and cellular mechanisms that may be involved in reinstatement. Recent studies have begun to implicate the MHb in cocaine-associated behaviors, yet the role of the MHb in regulating reinstatement of cocaine self-administration remains largely unknown. Recent work in the lab has identified the histone deacetylase 3 (HDAC3; a powerful epigenetic regulator of gene expression) target gene, Nr4a2, as an important regulator of cocaine-associated behavior. NR4A2 is a transcription factor that regulates aspects of dopamine signaling during development, and is densely expressed in the MHb. I will test the central hypothesis that the MHb regulates reinstatement of cocaine self-administration in an NR4A2-dependent manner. Specifically, I will examine the role of Nr4a2, in MHb-dependent reinstatement of cocaine self-administration using viral expression of NURR2C, an endogenously occurring NR4A2 dominant negative splice variant, or wild-type NR4A2 to bidirectionally regulate NR4A2 function. My preliminary data show that NURR2C animals have reduced reinstatement, identifying NR4A2 in the MHb as a key regulator of reinstatement behavior. To develop a more in-depth understanding of the MHb response to cocaine-seeking behavior as well as self-administration, extinction training, and withdrawal, I will use single nuclei RNA sequencing to look for changes in cell type proportions, gene expression and gene networks. Within these analyses I will also look for NR4A2-dependent changes and sex-dependent changes. Completion of the proposed research will significantly advance our understanding of the MHb in reinstatement, and provide important insight into NR4A2 and NR4A2-dependent gene regulation. This training fellowship will allow me to develop molecular and bioinformatics expertise. With the guidance of both Dr. Wood and Dr. Swarup and the research and professional development environment at UCI, this fellowship will provide a foundation for a successful career as an independent investigator focused on understanding the molecular mechanisms of learning and memory that contribute to relapse to drug-seeking behavior.