Dopamine circuit regulation of morphine reinforcement across the opioid exposure cycle

项目总结 腹侧被盖区(VTA)多巴胺系统与慢性暴露相关的病理适应 对阿片类药物和阿片类药物戒断的反应可以失调对阿片类药物和上下文线索联系的反应。这个 本培训计划的主要目标是获得高级计算技术方面的新技能，以描述 不同功能亚群的VTA多巴胺神经元在吗啡暴露中是如何调节的 以及在非依赖和吗啡依赖小鼠中吗啡上下文关联的形成。 基础性发现已经确定了固有的和突触的(谷氨酸和GABA能)适应 VTA多巴胺神经元在急性和慢性阿片类药物暴露过程中经历。然而，很少有研究表明 解释了VTA多巴胺神经元调节线索奖赏不同方面的功能多样性 过程和动力。分离VTA多巴胺反应在发育过程中的潜在多样性 对阿片类药物依赖的研究将有助于揭开阿片使用障碍进展的神经基础。兹韦费尔 Lab之前曾使用遗传方法分离出功能不同的多巴胺神经元亚群 它投射到伏隔核(NAC)的离散区域。促肾上腺皮质激素释放激素受体1 (CRHr1)-CRE VTA多巴胺神经元选择性地投射到NAc核(Vta核)和 CCK-CRE VTA多巴胺能神经元选择性地投射到NAc内侧壳(VtamShell)。我 假设存在特定于投射的神经和行为与吗啡和 在非依赖和吗啡依赖小鼠的吗啡背景联系形成过程中。我 将在三个目标上使用系统的方法来调查这一点。对于目标1(K99)，我将使用行为 药理学和纤维光度法检测Vta核心和VtamShell多巴胺神经元 非依赖和吗啡参与均匀或不同剂量依赖的神经激活动力学 依赖的小鼠。对于目标2(K99)，我将使用我在条件位置偏好和体内纤维方面的技能 光度法确定Vta核心神经元和VtamShell神经元如何编码上下文关联 非依赖和吗啡依赖小鼠的吗啡。对于目标3(R00)，我将确定这些基础 解剖Mu-阿片受体(MOR)在VTA多巴胺亚群中的病理适应作用 敏感的GABA能输入在吗啡的背景联系中起作用。在K99指导阶段，我将 在拉里·茨韦费尔博士的实验室获得新的科学培训，并得到我的顾问委员会的加强， 用于分析复杂的神经生理和行为数据集的计算分析工具。我也会收获 来自Zweifel博士、我的顾问委员会和Mosaic UE5计划的新职业发展培训 将有助于我转变为学术界一名成功的独立首席研究员。重要的是，我会 继续我在增加生物医学研究劳动力的代表性和公平性方面的工作。

PROJECT SUMMARY Pathological adaptions in the ventral tegmental area (VTA) dopamine system associated with chronic exposure to opioids and opioid withdrawal can dysregulate responsivity to opioids and contextual cue associations. The primary goal of this training proposal is to gain new skills in advanced computational techniques to delineate how functionally diverse subpopulations of VTA dopamine neurons are regulated during morphine exposure and the formation of morphine contextual associations in non-dependent and morphine-dependent mice. Foundational findings have identified the intrinsic and synaptic (glutamatergic and GABAergic) adaptations that VTA dopamine neurons undergo throughout acute and chronic opioid exposure. Yet, few studies have accounted for the functional diversity of VTA dopamine neurons that mediate distinct aspects of cue-reward processing and motivation. Dissociating the potential diversity of VTA dopamine responses in the development of opioid dependence will help unravel the neural basis of the progression of opioid-use disorder. The Zweifel lab has previously used a genetic approach to isolate functionally distinct subpopulations of dopamine neurons that project to discrete regions of the nucleus accumbens (NAc). Corticotrophin releasing hormone receptor 1 (Crhr1)-Cre VTA dopamine neurons were found to selectively project to the NAc Core (VTACore) and cholecystokinin (Cck)-Cre VTA dopamine neurons selectively project to the NAc medial Shell (VTAmShell). I hypothesize that there exist projection-specific neural and behavioral correlates in response to morphine and during the formation of morphine contextual associations in non-dependent and morphine-dependent mice. I will investigate this using a systematic approach across three aims. For Aim 1 (K99), I will use behavioral pharmacology and fiber photometry to determine whether VTACore and VTAmShell dopamine neurons engage in uniform or differential dose-dependent neural activation dynamics in non-dependent and morphine dependent mice. For Aim 2 (K99), I will use my skills in conditioned place preference and in vivo fiber photometry to determine how the VTACore and VTAmShell neurons encode contextual associations to morphine in non-dependent and morphine dependent mice. For Aim 3 (R00), I will determine the basis of these pathological adaptations in VTA dopamine subpopulations by dissecting the role mu-opioid receptor (MOR)- sensitive GABAergic inputs play in morphine contextual associations. During the K99 mentored phase, I will gain new scientific training in Dr. Larry Zweifel’s laboratory, augmented by my advisory committee, in computational analytical tools to analyze complex neurophysiological and behavioral data sets. I will also gain new career development training from Dr. Zweifel, my advisory committee, and the MOSAIC UE5 program that will facilitate my transition into a successful independent principal investigator in academia. Importantly, I will continue my work on increasing representation and equity in the biomedical research workforce.