Dissecting stress modulation of pnVTA nociceptin peptide-mediated approach-avoidance behavior

项目摘要：慢性应激导致许多疾病的发病和恶化 在包括药物使用障碍在内的寻求奖励行为中经常表现出非典型动机的 (SUD)、严重抑郁障碍(MDD)和焦虑。压力会在多大程度上扰乱动力 取决于压力暴露的形式。因此，了解神经回路的调节动机是至关重要的。 在不同的慢性压力状态下，行为会被打乱，以提高我们对这些 疾病的发展，是什么使一些个体更容易受到影响，并识别更有效的分子 治疗靶点。我们的实验室此前曾报道，产生内源性阿片肽的神经元 黑质旁腹侧被盖区的伤害素(pnVTAPnoc神经元)局部作用于伤害素受体 (NOPR)限制奖励动机(Parker等人，Cell，2019)，而其他人则确定了伤害素的作用 在精心安排的压力反应中发出信号。初步数据显示，pnVTA伤害素神经元 被不同的压力源动态地投入到不同的程度。这项提议的中心假设是 应激差异地参与pnVTA伤害素信号，以调节动机行为的表达 作为接近避让。这项提议是对NIDA战略目标1的直接回应，战略目标1旨在调查 有助于大脑功能的电路“，如奖励、动机、决策…以及压力反应性，“ 同时研究NIDA对SUD的高优先级目标。目标1将确定不同的物理和 心理应激源在分子和功能水平上改变VTA伤害素阿片系统。目标1A将 评估各种应激源如何急性和慢性地改变VTA伤害素/NOPR的表达和神经元 活动。目的1B使用一种新的基因编码的伤害素多肽生物传感器(NOPLight)，并头- 固定接近-回避(AP-Av)行为模型，以确定VTA中伤害素的释放如何改变 在压力暴露后的AP-Av决策过程中。AIM 1C使用前胶原(PNOC)条件性治疗 创造了内部和光遗传学来操纵VTA伤害素多肽的表达和活性的基因敲除系 紧随压力而来。目标2将确定下丘脑外侧的解剖和功能受累 (1H)作为传入输入调节幼稚和应激状态下的pnVTAPnoc神经元活动 电生理学和纤维光度法同时记录大鼠LH末梢活动和伤害素释放 慢性压力暴露后的室上性心动过速利用这些新方法将使我们能够提供品牌 对这个鲜为人知的系统的新洞察。在我的培训期间，我将学习使用尖端技术 技术，以便对神经肽回路进行强大的、高分辨率的研究，并获得 通过一系列科学的、智力的和有指导的编程进行有价值的职业发展培训。这 F31机制将使我能够追求我的个人发展计划，并为我的职业生涯做好准备 独立的神经学家。

PROJECT SUMMARY: Chronic stress contributes to the pathogenesis and exacerbation of numerous disorders that frequently present with atypical motivation during reward-seeking behavior including substance use disorder (SUD), major depressive disorder (MDD), and anxiety. The extent to which motivation is disrupted by stress can depend on the form of stress exposure. Hence, it is critical to understand the neural circuitry regulating motivated behaviors become disrupted under diverse chronic stress states to improve our understanding of how these disorders develop, what makes some individuals more susceptible, and to identify more effective molecular therapeutic targets. Our laboratory previously reported that neurons producing the endogenous opioid peptide nociceptin in the paranigral ventral tegmental area (pnVTAPnoc neurons) act locally on nociceptin receptor (NOPR) to limit motivation for reward (Parker et al, Cell, 2019), while others have identified a role for nociceptin signaling in the orchestrated stress response. Preliminary data show that pnVTA nociceptin neurons are dynamically engaged to different extents by distinct stressors. The central hypothesis of this proposal is that stress differentially engages pnVTA nociceptin signaling to regulate the expression of motivated behaviors such as approach-avoidance. This proposal is in direct response to NIDA’s Strategic Goal 1 which aims to investigate circuitry contributing to brain functions “such as reward, motivation, decision-making…and stress reactivity, ” alongside examining a NIDA high priority target for SUD. Aim 1 will determine how diverse physical and psychological stressors alter the VTA nociceptin opioid system on a molecular and functional level. Aim 1A will evaluate how various stressors acutely and chronically alter VTA nociceptin/NOPR expression and neuron activity. Aim 1B uses a new genetically encoded biosensor for the nociceptin peptide (NOPLight), and head- fixed approach-avoidance (Ap-Av) behavioral models to determine how nociceptin release in the VTA is altered during Ap-Av decision making following stress exposure. Aim 1C uses prepronociceptin (Pnoc) conditional knockout line created in-house and optogenetics to manipulate VTA nociceptin peptide expression and activity following stress. Aim 2 will determine the anatomical and functional involvement of the lateral hypothalamus (LH) as an afferent input regulating pnVTAPnoc neuron activity in naïve and stressed states using electrophysiology and fiber photometry to simultaneously record LH terminal activity and nociceptin release in the VTA following chronic stress exposure. Leveraging these new approaches will enable us to provide brand new insight into this poorly understood system. During my training period I will learn to utilize cutting-edge techniques in order to perform powerful, high-resolution investigations of neuropeptide circuitry, and gain valuable career development training across a host of scientific, intellectual, and mentored programming. This F31 mechanism will allow me to pursue my individual development plan and prepare me for a career as an independent neuroscientist.