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

项目摘要/摘要 物质使用障碍因终身复发的风险而变得复杂。故态复萌的漏洞部分地被编程 在吸毒过程中，当滥用药物的行为在奖赏回路中能够形成异常时 强烈的背景/奖励记忆。这些记忆过程是常见的复发触发因素，如暴露 与毒品相关的线索或环境有关，并可能持续极长时间。这种持久性可以归因于 对于表观遗传学(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)，这已被证明在细胞中建立稳定的变化 功能，进而改变行为结果。这项提案的重点是研究分子和 可能参与恢复的细胞机制。最近的研究已经开始将MHB与 可卡因相关行为，但MHB在调节恢复可卡因自我给药中的作用 在很大程度上仍不为人所知。实验室最近的工作已经确定了组蛋白脱乙酰基酶3(HDAC3；一种强大的 基因表达的表观遗传调节)靶基因Nr4a2作为可卡因相关的重要调节基因 行为。NR4A2是一种转录因子，在发育过程中调节多巴胺信号的各个方面，并且 在MHB中密集表达。我将测试MHB监管恢复的核心假设 可卡因以NR4A2依赖的方式自我给药。具体地说，我将研究Nr4a2在 MHB依赖的NURR2C病毒表达恢复可卡因自身给药 内源性NR4A2显性负剪接变异体，或野生型NR4A2双向调控 NR4A2功能。我的初步数据显示，NURR2C动物的恢复能力有所下降，发现 NR4A2在MHB中作为恢复行为的关键调节因子。为了更深入地了解 MHB对可卡因寻找行为以及自我管理、灭绝训练和戒断的反应， 我将使用单核RNA测序来寻找细胞类型比例、基因表达和基因的变化 网络。在这些分析中，我还将寻找NR4A2依赖的变化和性别依赖的变化。 建议研究的完成将大大促进我们对房屋及房屋局复职的了解， 为NR4A2和NR4A2依赖的基因调控提供了重要的见解。这项培训奖学金将 请允许我介绍一下分子和生物信息学方面的专业知识。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，这一奖学金将为 作为一名成功的独立研究人员，他专注于了解 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.