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

项目概要：慢性应激导致许多疾病的发病机制和恶化 在寻求奖励的行为中经常表现出非典型的动机，包括物质使用障碍 (SUD)抑郁症（MDD）和焦虑症。压力在多大程度上扰乱了动机， 取决于压力暴露的形式。因此，了解调节动机的神经回路是至关重要的 行为在不同的慢性压力状态下会被破坏，以提高我们对这些行为如何被破坏的理解。 疾病的发展，是什么使一些人更易感，并确定更有效的分子 治疗目标我们实验室先前报道，产生内源性阿片肽的神经元 黑质旁腹侧被盖区（pnVTAPnoc神经元）的痛敏素局部作用于痛敏素受体 （NOPR）限制奖励动机（帕克等人，细胞，2019），而其他人已经确定了伤害感受素的作用 在协调的压力反应中发出信号。初步数据显示，pnVTA痛肽神经元是 不同的压力源在不同程度上动态地参与。这一提议的核心假设是， 应激差异性地参与pnVTA伤害感受素信号传导，以调节动机性行为的表达， as approach接近-avoidance避免.这一提议是对NIDA战略目标1的直接回应，该目标旨在调查 负责大脑功能的回路，“如奖励、动机、决策......和压力反应“， 同时研究了NIDA对SUD的高优先级目标。目标1将决定如何多样化的身体和 心理应激源在分子和功能水平上改变腹侧被盖区痛敏肽阿片样物质系统。目标1A将 评估各种应激源如何急性和慢性改变腹侧被盖区伤害感受素/NOPR表达和神经元 活动目的1B使用一种新的基因编码的生物传感器的伤害感受肽（NOPLight），和头部- 固定的接近-回避（Ap-Av）行为模型，以确定VTA中的伤害感受素释放是如何改变的 在压力暴露后的Ap-Av决策过程中。Aim 1C使用前原感受肽（Pnoc）条件 内部和光遗传学创建敲除系以操纵VTA痛敏肽表达和活性 压力之后。目的2将确定外侧下丘脑的解剖和功能参与 (LH)作为传入输入，调节幼稚和应激状态下的pnVTAPnoc神经元活动，使用 电生理学和纤维光度法同时记录LH末端活性和痛敏素释放， 腹侧被盖区的损伤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有了新的认识。在我的培训期间，我将学习利用尖端技术 技术，以执行强大的，高分辨率的神经肽电路的调查，并获得 在一系列科学，智力和指导性的编程中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。 独立神经科学家

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.