Defining the Role of D1 and D2 Medium Spiny Neurons in Relapse to Cocaine Seeking

项目摘要 环境背景和经验之间的经验联系是决策的基础， 允许生物体引导行为朝向有利的结果。神经过程功能障碍 调节这些联系的神经元，特别是在丘脑核（NAc）中，是病理学中的关键因素 上瘾的人NAc是主要由两种相反的细胞类型组成的异质区域：D1和D2 中棘投射神经元（MSNs）。这些细胞的光遗传刺激导致不同的行为 输出;因此，重要的是要研究这些群体在隔离，以了解细胞类型的具体信号 这是NAC介导的学习过程的基础。在Eric Nestler博士和Paul博士的主要指导下， 肯尼在纽约西奈山伊坎医学院，独立之路奖将 提供机会，以建立我的专业知识，可卡因自我管理和突触功能， 同时发展我在体内钙成像和光遗传学方面的培训和专业知识。在 指导的K-阶段，这格兰特纤维光度钙成像将与可卡因自我管理配对 在D1或D2 MSN群体中表达Cre重组酶转基因小鼠品系中。这些老鼠允许 分子靶点的细胞类型特异性表达，例如钙指示剂（GCaMP 6 f）和视蛋白（ChR 2; NpHR）。通过在D1或D2 MSNs中表达GCaMP 6 f，介导线索诱导的时间特异性信号被激活。 可卡因将被确定。此外，光遗传学刺激和抑制将允许直接遗传学效应。 操纵这些细胞和相关的寻找行为。这些工具的创新组合将 使得能够映射D1和D2 MSN如何编码提示信息并同时建立因果关系。在 独立阶段（R 00），这些尖端技术将与诱导型ArcCreERT 2相结合 在被环境激活的细胞中选择性表达构建体（GCaMP 6 f/视蛋白）的小鼠 在特定时间窗口期间的刺激。这将允许记录和操纵神经元 可卡因或可卡因配对线索激活的合奏，以确定他们在药物寻求中的作用。 总之，这些数据将阐明控制联想学习的潜在神经过程以及如何控制联想学习。 可卡因暴露会使MSN信号失调，从而导致戒断后复发，这将扩大我们的研究范围。 对成瘾的基本理解，并可能导致新的治疗途径的发展。总的来说， 在这个独立之路奖中提出的研究将阐明相关的神经机制， 在上瘾的同时，我准备开发一个完全独立的研究计划， 整合了广泛的基于电路和行为的方法来剖析成瘾的神经生物学。 .

Project Summary Learned associations between environmental contexts and experience are the basis of decision-making and allow organisms to guide behavior towards advantageous outcomes. Dysfunction in the neuronal processes that regulate these associations, especially in the nucleus accumbens (NAc), is a critical factor in the pathology of addiction. The NAc is a heterogeneous region primarily composed of two opposing cell types: D1 and D2 medium spiny projection neurons (MSNs). Optogenetic stimulation of these cells results in divergent behavioral outputs; thus, it is important to study these populations in isolation to understand the cell-type specific signals that underlie NAc-mediated learning processes. Under the primary mentorship of Dr. Eric Nestler and Dr. Paul Kenny at Icahn School of Medicine at Mount Sinai in New York, the Pathway to Independence Award will provide the opportunity to build on my expertise in cocaine self-administration and synaptic function while simultaneously developing my training and expertise in in vivo calcium imaging and optogenetics. In the mentored K-phase of this grant fiber photometry calcium imaging will be paired with cocaine self-administration in transgenic mouse lines that express Cre-recombinase in D1 or D2 MSN populations. These mice allow for cell-type specific expression of molecular targets, such as calcium indicators (GCaMP6f) and opsins (ChR2; NpHR). By expressing GCaMP6f in D1 or D2 MSNs, the temporally specific signals that mediate cue-induced cocaine seeking will be determined. Further, optogenetic stimulation and inhibition will allow for direct manipulation of these cells and the associated seeking behavior. The innovative combination of these tools will enable the mapping of how D1 and D2 MSNs encode cue information and concurrently establish causality. In the independent phase (R00), these cutting-edge techniques will be combined with the inducible ArcCreERT2 mice which express constructs (GCaMP6f/Opsins) selectively in cells that are activated by environmental stimuli during a temporally specific window. This will allow for the recording and manipulation of neuronal ensembles that are activated by cocaine or cocaine-paired cues to determine their role in drug seeking. Together, these data will elucidate the underlying neural processes that control associative learning and how cocaine exposure dysregulates MSN signaling to drive relapse following abstinence, which will expand our basic understanding of addiction and may lead to the development of novel therapeutic avenues. In summary, the research proposed in this Pathway to Independence Award will elucidate the neural mechanisms involved in addiction while simultaneously preparing me to develop a fully independent research program capable of integrating a wide range of circuit based and behavioral approaches to dissect the neurobiology of addiction. .