Nucleus accumbens fast-spiking interneurons regulate opioid reward and addiction

项目摘要 阿片类药物成瘾是一种公共卫生危机，其特征是强迫性药物寻求和普遍的 易复发，可用的治疗选择很少。神经核（NAc）是一个中枢， 在奖赏回路中，在药物和药物相关线索的激励价值中起着关键作用。内 NAc的异质神经元亚型存在稀疏分布的快速发放中间神经元（FSI）。 NAc FSI接受来自皮质、丘脑和边缘系统区域的强兴奋性输入， 抑制局部投射神经元，使其成为翻译治疗的主要候选者 减轻阿片类药物滥用流行病负担的战略。本申请的总体目标是 阐明NAc FSI电路如何响应和介导阿片类药物自我给药。 在明尼苏达大学帕特里克罗斯韦尔博士的主要指导下， 利用分子和行为药理学技术的研究生培训，以及前 体内电生理学研究非偶然阿片类成瘾模型中NAc回路的适应。这 独立之路奖将提供机会，以扩大候选人的专业知识，包括在 在Rothwell博士的继续指导下，研究了体内纤维光度测定钙成像和化学遗传学。到 扩大成瘾研究的职业发展，Lefevre博士将获得共同导师Dr. Mark托马斯在雌性和雄性小鼠中实施应急阿片类药物自我给药模型。 在指导（K99）阶段的奖励，纤维光度钙成像将用于监测 在间歇进入（IntA）芬太尼自我给药方案中NAc FSI的体内活性模式，以确定 这个神经群体如何对偶然的芬太尼和芬太尼相关的线索做出反应。随后 化学遗传学方法，其将涉及通过特异性激活的设计者受体的靶向表达。 NAc FSI的设计药物（DREADDs）将用于测试这些神经元发挥功能的假设。 在成瘾相关行为中的作用。芬太尼自我给药后，DREADD将用于激发或 抑制NAc FSI前进行的比率和线索诱导的恢复测试。这种创新的组合， 将使用工具来测试NAc FSI与芬太尼自我给药表现之间的关系。 该奖项的R00阶段将把Lefevre博士的独立研究与她的导师区分开来， 扩大到确定兴奋性突触输入NAc FSI的作用。将利用离体电生理学 定义芬太尼自身诱导的NAc FSI中的输入特异性兴奋性突触可塑性适应， 局此外，R00 aims将整合电生理学、光遗传学和钙成像 专业知识，以开发刺激方案，恢复阿片类药物诱导的FSI电路和成瘾样变化 行为总的来说，本奖项提出的目标将确定阿片类药物自我管理的关键FSI电路， 为Lefevre博士研究成瘾神经回路的独立研究项目提供了基础。

Project Abstract Opioid addiction is a public health crisis, characterized by compulsive drug seeking and a pervasive vulnerability to relapse, with few therapeutic options available. The nucleus accumbens (NAc) is a central hub within reward circuitry and plays a critical role in the motivational value of drugs and drug-associated cues. Within the heterogeneous neuronal subtypes of the NAc exist the sparsely distributed fast-spiking interneurons (FSIs). The NAc FSIs receive strong excitatory inputs from cortical, thalamic and limbic regions and exert powerful inhibition over the local projection neurons, making them a prime candidate for translational therapeutic strategies to reduce the burden of the opioid abuse epidemic. The overall objectives of this application are to elucidate how NAc FSI circuitry responds to, and mediates, opioid self-administration. Under the primary mentorship of Dr. Patrick Rothwell at the University of Minnesota, Dr. Lefevre has utilized graduate training in molecular and behavioral pharmacology techniques, and post-doctoral training in ex- vivo electrophysiology to study adaptations in NAc circuitry in non-contingent opioid addiction models. This Pathway to Independence Award will provide the opportunity to broaden the candidate’s expertise to include in vivo fiber photometry calcium imaging, and chemogenetics, under the continued mentorship of Dr. Rothwell. To expand career development in addiction research, Dr. Lefevre will receive additional support from co-mentor Dr. Mark Thomas in the implementation of contingent opioid self-administration models in female and male mice. During the mentored (K99) phase of the award, fiber photometry calcium imaging will be used to monitor in vivo activity patterns of NAc FSIs in an Intermittent Access (IntA) fentanyl self-administration protocol to identify how this neural population responds to contingent fentanyl and fentanyl-associated cues. Subsequently, a chemogenetic approach, which will involve targeted expression of Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) by NAc FSIs, will be used to test the hypothesis that these neurons play a functional role in addiction-related behavior. Following fentanyl self-administration, DREADDs will be used to excite or inhibit NAc FSIs prior to progressive ratio and cue-induced reinstatement tests. This innovative combination of tools will be used to test the relationship between NAc FSIs and the manifestation of fentanyl self-administration. The R00 phase of the award will distinguish Dr. Lefevre’s independent research from her mentors and broaden to identifying the role of excitatory synaptic inputs to NAc FSIs. Ex-vivo electrophysiology will be utilized to define input-specific excitatory synaptic plasticity adaptations in NAc FSIs induced by fentanyl self- administration. Additionally, the R00 aims will incorporate electrophysiology, optogenetic and calcium imaging expertise to develop stimulation protocols that restore opioid induced shifts in FSI circuitry and addiction-like behavior. Overall, the aims proposed in this award will identify key FSI circuits in opioid self-administration and provide the foundation for Dr. Lefevre’s independent research program studying the neural circuitry of addiction.