Transcriptional reprogramming of drug-associated memories in the nucleus accumbens

项目摘要 物质使用障碍(SUD)的特征是反复吸毒行为，这种行为往往类似于成功的基于戒毒的治疗后更新诱导的复发。当受试者重新接触原始药物环境(即他们的家)时，这种无法转移获得性灭绝的能力与伏隔核(NAC)等神经区域的缺陷有关，NAC调节与药物相关的记忆的消失及其维持自愿戒断的能力。例如，成瘾者在特定的情境A中发展成瘾，可能会在临床情境B中消除对药物相关线索的反应，但当再次暴露于情境A中的相同线索时，无法将习得的消退转移到抑制情境诱导的更新/复发。因此，由于停止寻找药物的能力依赖于克服与药物相关的记忆，灭绝代表了一个临床前的机会，以表征和操纵潜在的药物寻找行为的分子底物，以克服与更新相关的复发。虽然药物自我给药(SA)会导致奖赏回路中大量神经可塑性的变化，但消退训练在重新编程与成瘾相关的行为和大脑奖赏回路的转录代码/结果方面的影响却知之甚少。总而言之，这些研究问题构成了一个平台，来勾勒出我目前的个人和专业培训计划，该计划将在我过渡到教员职位时应用。在我的主要导师(Eric Nestler博士：发起人和Paul Kenny博士：共同发起人)和我的指导委员会(Mary Kay Lobo博士、Yavin Shaham博士、Li Sheni和Fabricio do Monte博士)的指导下，我将使用RNA测序技术对接受可卡因-SA和上下文消亡(AAA Vs ABA)或戒断(无消亡)程序的大鼠的NAC亚区(核心和外壳)进行测序，在转录水平(目标1)表征与药物相关的记忆(表型；更新和消亡)。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。具体地说，我将设计新的病毒载体来执行病毒介导的基因转移，以操纵先前被证明或新推导的顶端HUB基因(即转录因子)，该基因是NAC中更新诱导复发(灭绝转移失败)的主要驱动因素，并以细胞特异性的方式进行。至于细胞特异性操作，我将利用在多巴胺D1或D2中培养的棘神经元(MSN)中表达CRE重组酶的新型转基因大鼠模型(目标2)。有目的地，因为涉及戒毒或因不良后果而服用药物之间的冲突的生活情况是复发的关键特征，我将在基于冲突的模型(目标3)中测试灭绝训练对恢复适应性决定的影响，在该模型中，寻求毒品导致应受惩罚的结果(即足部电击)，以更深入地研究与人最相关的灭绝/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.