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，极有必要深入了解阿片类药物。 在细胞和电路层面上的行动和潜在的机制。纹状体整合 来自相互连接的皮质和丘脑的兴奋性输入，形成一个三角回路，调节 关键的大脑功能，包括运动控制、情感痛苦、决策和奖励。阿片类药物 对这一回路施加强有力的调制，但他们的具体行动，例如他们在哪里行动和如何行动， 还没有完全被理解。我们提案的首要目标是全面阐明 丘脑-皮质-纹状体三角环路中的个别元素受不同的阿片类药物调制 受体激动剂以及这些调节如何改变电路的功能。 丘脑-皮质-纹状体回路是根据皮质内的特定亚区组织的， 丘脑和纹状体。在上一次融资期间，我们建立了第一个全面的 丘脑-皮质-纹状体回路接线图，它使我们能够识别和划定次区域- 特定的连接性。在我们的初步研究中，我们已经确定了 前扣带回皮质(ACC)和内侧背核(MD)丘脑，这两个都在 在背内侧纹状体(DMS)，情绪性疼痛和奖励。该MD-ACC-DMS电路可能 推动与痛苦和奖励相关的执行功能。阿片受体的不同亚型有 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， 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 在这个环路中，亚区的特征很差。在目前的提案中，我们将使用尖端工具 解剖特定的子区、特定的细胞类型、特定的阿片受体类型和特定的突触 MD-ACC-DMS回路中突触的调制。具体来说，我们将利用我们的 独特的研究优势，包括我们在 在之前的资助期，我们新的成像能力可以直接显示亚细胞cAMP/PKA 活体组织阿片受体下游信号传递及新型脑片的建立 为监测阿片类药物对多突触信息传播的调制做准备。使用这些 方法，我们将确定作用部位(目标1)，潜在的细胞内信号机制 (目标2)，以及不同激活的阿片受体的功能影响(目标3)。我们的建议 实验将导致对阿片受体在脑内的作用有一个深入的、机械的理解。 MD-ACC-DMS电路，可促进制定更有效地解决 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.