Transcriptional reprogramming of drug-associated memories in the nucleus accumbens

项目摘要 物质使用障碍（SUD）的特征是反复的吸毒行为，通常类似于成功的基于预防的治疗后的更新诱导的复发。当受试者重新暴露于原始药物环境时，这种无法转移习得性消退（即，这些药物（在他们的家中）与神经区域的缺陷有关，如神经核（NAc），它调节与药物有关的记忆的消失及其保持自愿戒断的能力。例如，在特定情境“A”中发展成成瘾的成瘾者可能在临床情境“B”中消除对药物相关线索的反应，但当在情境“A”中再次暴露于相同线索时，不能转移习得性消退以抑制情境诱导的更新/复发。因此，由于停止药物寻求的能力依赖于克服药物相关的记忆，因此消退代表了表征和操纵药物寻求行为背后的分子底物以克服更新相关复发的临床前机会。虽然药物自我给药（SA）导致奖励回路中的许多神经可塑性变化，但对灭绝训练在重新编程大脑奖励回路的成瘾相关行为和转录组代码/结果中的影响知之甚少。总之，这些研究问题构成了一个平台，以描绘我目前的个人和专业培训计划，这将适用于我过渡到教师的位置。在我的初级导师的指导下（Eric Nestler博士：申办方和Paul Kenny博士：和我的指导委员会（玛丽凯·洛博、亚文·沙哈姆、李申和法布里西奥·多蒙特博士），我将使用NAc亚区的RNA测序，（核心和外壳）接受可卡因-SA和上下文灭绝的大鼠（AAA对阿坝）或戒断（无消退）程序，以在转录水平上表征药物相关记忆（表型;更新对消退）（目的1）。随后，为了操纵由此产生的行为，我将针对NAc亚区和细胞类型的转录组。具体来说，我将设计新型病毒载体来进行病毒介导的基因转移，以操纵顶部枢纽基因（即，转录因子）先前被证明或新推断为NAc中亚区和细胞特异性方式的更新诱导复发（消退转移失败）的主要驱动因素。至于细胞特异性操作，我将利用在多巴胺D1或D2介质棘神经元（MSN）中表达Cre重组酶的新型转基因大鼠模型（Aim 2）。有目的地，因为涉及因不良后果而放弃或服用药物之间的冲突的生活情况是复发的一个关键特征，我将测试灭绝训练对基于冲突的模型（目标3）中恢复适应性决策的影响，其中寻求药物导致可惩罚的结果（即，footshocks），深入研究与人类最相关的灭绝/更新的神经生物学。

Project Summary Substance use disorder (SUD) is characterized by recurrent drug-taking behaviors that often resemble the renewal-induced relapse after a successful extinction-based therapy. This inability of transferring the learned extinction as the subjects are re-exposed to the original drug context (i.e., their homes) is associated with deficits in neural regions such as the nucleus accumbens (NAc), which regulates the extinction of drug-associated memories and its ability to maintain voluntary abstinence. For instance, addicts developing addiction in a particular context “A” may extinguish the responses for drug-associated cues in a clinical context “B”, but when re-exposed to the same cues in context “A”, fail to transfer the learned extinction to suppress the context-induced renewal/relapse. Thus, because the ability to cease drug-seeking relies on overcoming drug-associated memories, extinction represents a preclinical opportunity to characterize and manipulate the molecular substrates underlying drug-seeking behavior to overcome the renewal-associated relapse. While drug self-administration (SA) leads to numerous neuroplasticity changes in the reward circuit, little is known about the impact of extinction training in reprogramming the addiction-relevant behavioral and transcriptomic codes/outcomes of the brain reward circuit. Together, these research questions pose a platform to delineate my current personal and professional training plan, which will be applied as I transition to a faculty position. Under the tutelage of my primary mentors (Drs. Eric Nestler: sponsor and Paul Kenny: co-sponsor) and my mentoring committee (Drs. Mary Kay Lobo, Yavin Shaham, Li Shen and Fabricio Do Monte), I will use RNA-sequencing of NAc subregions (core and shell) of rats receiving cocaine-SA and contextual extinction (AAA vs ABA) or withdrawal (no extinction) procedures, to characterize the drug-associated memories (phenotypes; renewal vs. extinction), at the transcriptional level (Aim 1). Subsequently, to manipulate the resulting behaviors, I will be targeting the transcriptome of NAc subregions and cell types. Specifically, I will design novel viral vectors to perform viral-mediated gene transfer to manipulate a top hub gene (i.e., transcription factor) previously proven or newly deduced as a main driver of renewal-induced relapse (failure of extinction transfer) in a subregion and cell-specific manner in NAc. As for the cell-specific manipulations, I will be utilizing the novel transgenic rat model expressing Cre-recombinase in dopamine D1 or D2 medium spiny neurons (MSNs) (Aim 2). Purposely, because life situations involving conflict between abstaining from or taking a drug due to adverse consequences are a key feature of relapse, I will test the impact of extinction training on restoring adaptive decisions in a conflict-based model (Aim 3), where drug seeking leads to punishable outcomes (i.e., footshocks), to delve deeper into the neurobiology of extinction/renewal that is most relevant to people.