Genetic and physiological dissection of the circuit mechanisms in the striatum.

项目摘要 随着阿片类药物危机的持续，人们迫切需要深入了解阿片类药物 在细胞和电路水平的行动和潜在的机制。纹状体整合 兴奋性输入从相互连接的皮层和丘脑，形成一个三角形电路，介导 关键的大脑功能，包括运动控制，情感疼痛，决策和奖励。阿片 但它们的具体动作，如“在哪里”和“如何”， 还没有被完全理解。我们提案的总体目标是全面阐明 丘脑-皮质-纹状体三角回路中的单个元件由不同的阿片类物质调节 受体激动剂以及这些调节如何改变回路的功能。 丘脑-皮质-纹状体回路是基于皮质内的特定子区域组织的， 丘脑和纹状体。在上一个供资期间，我们建立了第一个全面的 丘脑-皮质-纹状体电路接线图，这使我们能够识别和描绘亚区- 具体的连通性。在我们的初步研究中，我们已经确定了确切的收敛网站的 前扣带皮层（ACC）和背内侧（MD）丘脑，这两者在 情感疼痛和奖励，在背内侧纹状体（DMS）。这个MD-ACC-DMS电路大概 驱动痛苦和奖励相关的执行功能。阿片受体的不同亚型 在这三个大脑区域都有表达，这使得这个回路很可能是阿片类药物的底物。然而，在这方面， 激动剂在特定阿片受体类型、细胞类型和大脑中的确切作用 在该电路中，子区域的特征很差。在目前的提案中，我们将使用尖端工具 解剖亚区域特异性、细胞类型特异性、阿片受体类型特异性和突触特异性 在MD-ACC-DMS回路中的突触的调制。具体来说，我们将利用我们的 独特的研究优势，包括我们在研究过程中获得的新的连接组学信息。 上一个资助期，我们的新的成像能力，直接可视化亚细胞cAMP/PKA 活组织中阿片受体下游的信号传导，以及我们建立新的脑切片 用于监测阿片样物质对多突触信息传播的调节的制剂。使用这些 方法，我们将确定的作用位点（目标1），潜在的细胞内信号传导机制 (Aim 2），以及不同的激活阿片受体的功能影响（目的3）。我们提出的 实验将导致深入，阿片受体的作用机制的理解， MD-ACC-DMS电路，可以促进战略的制定，以更有效地解决 阿片类药物在镇痛和成瘾中的作用。

PROJECT ABSTRACT With the ongoing opioid crisis, there is a tremendous need for an in-depth understanding of opioid actions and the underlying mechanisms at the cellular and circuit levels. The striatum integrates excitatory inputs from the interconnected cortex and thalamus to form a triangular circuit that mediates critical brain functions, including motor control, affective pain, decision-making, and reward. Opioids impose strong modulation of this circuit, but their specific actions, such as “where” and “how” they act, are not fully understood. The overarching goal of our proposal is to comprehensively elucidate how individual elements in the thalamo-cortico-striatal triangular circuit are modulated by distinct opioid receptor agonists and how these modulations alter the function of the circuit. The thalamo-cortico-striatal circuit is organized based on specific subregions within the cortex, thalamus, and striatum. During the previous funding period, we established the first comprehensive thalamo-cortico-striatal circuit wiring diagram, which allowed us to identify and delineate subregion- specific connectivity. In our preliminary studies, we have identified the exact convergent sites of the anterior cingulate cortex (ACC) and the mediodorsal (MD) thalamus, both of which play critical roles in affective pain and reward, in the dorsomedial striatum (DMS). This MD-ACC-DMS circuit presumably drives pain and reward-associated executive functions. Different subtypes of opioid receptors are expressed in all three of these brain regions, making this circuit a likely substrate for opioids. However, the precise actions of agonists in the context of specific opioid receptor types, cell types, and brain subregions are poorly characterized in this circuit. In the current proposal, we will use cutting-edge tools to dissect subregion-specific, cell type-specific, opioid receptor type-specific, and synapse-specific modulation of the synapses in the MD-ACC-DMS circuit. Specifically, we will take advantage of our unique research strengths, including the novel connectomic information we acquired during the previous funding period, our novel imaging capability for directly visualizing subcellular cAMP/PKA signaling downstream of opioid receptors in living tissue, and our establishment of novel brain slice preparations for monitoring opioid modulation of multi-synaptic information propagation. Using these approaches, we will identify the action sites (Aim 1), the underlying intracellular signaling mechanisms (Aim 2), and the functional impacts (Aim 3) of distinct activated opioid receptors. Our proposed experiments will result in an in-depth, mechanistic understanding of the actions of opioid receptors in the MD-ACC-DMS circuit that may facilitate the development of strategies to more effectively address the role of opioids in analgesia and addiction.