Physiological and Molecular Mechanisms of Mu Opioid Receptors in Motivation and Affect

项目总结： 这项培训计划的主要目标是了解阿片受体如何以机械性的粒度。 (MORS)调节伏隔核(NAC)中动机的“想要”与情绪性的“喜欢”。在建议的 K99培训期间，我将接受两种活体生理学/成像方法(纤维光度和单光子)的培训 显微镜)和细胞内/分子效应系统。此外，我还将积极参与 专业/职业培训机会，并经常与我的指导委员会开会准备 申请并在独立的教职岗位上取得成功。我的建议的第一个研究目的是寻求 了解内源性MOR信号在DRNEnkNAC通路中的时间动力学和作用。我的 以前的博士后研究，利用药理学、遗传学和光遗传学/化学遗传学，已经发现 脑啡肽能中缝背核的终末投射到NAc作为MOR作用的部位 调节食物摄取行为。为了更好地理解MOR信号如何影响这一途径，我将使用两个 体内成像方法，纤维光度法和显微内窥镜，以确定内源性MOR信号 在激励行为中塑造神经回路活动(目标1，K99)。此外，因为特定的角色 细胞内信号级联在大脑奖励回路中还没有很好的定义，我将操纵G蛋白 和β-arrestin信号通路，以确定它们各自如何影响行为(目标2，K99)。在.期间 在K99阶段，我还将准备领导自己的研究实验室。我会积极投身科学社会 领导职位(主持座谈会、指导委员会)，学习如何指导实验室(预算和 管理任务)，并继续加深我的学术知识基础(与我的导师有计划的互动 和委员会成员)。对于我的建议的R00“独立”阶段，我建议在被指导的 上面的训练是为了研究在NAC(AIM)中，是什么机制和回路构成了MOR介导的情感“喜欢” 3)。这些研究令人感兴趣，因为越来越多的证据表明，尽管NAC MORS可以强有力地 调节动机和情感，它们可能通过不同的神经机制做到这一点。了解这些功能是如何 生物心理系统是可分离的，即使在特定的神经化学类别中，也有重要的意义 用于开发既有效又不存在滥用倾向的新型治疗药物。这就做 使用多种遗传小鼠模型和病毒载体干预，选择性地干扰或恢复MOR功能， 以及使用显微内窥镜方法记录体内内源性神经元反应。我会表演的 这些实验同时测试了小鼠的情感测试反应性(TR)测试，该测试对 先天口腔面部对味觉刺激的反应，几十年来一直被有效地用来测量情感 味觉刺激的价值。从这些学习和指导机会中获得的知识将大大 促进我自己的研究项目的发展，为我职业生涯的下一阶段做好准备。

Project Summary: The primary goal of this training proposal is to understand, with mechanistic granularity, how mu opioid receptors (MORs) modulate motivated `wanting' versus affective `liking' in nucleus accumbens (NAc). During the proposed K99 training period, I will be trained in two in vivo physiology/imaging approaches (fiber photometry and 1-photon microscopy) and on intracellular/molecular effector systems. Additionally, I will actively participate in professional/career training opportunities and have frequent meetings with my mentoring committee to prepare to apply and succeed in an independent faculty position. The first research aim of my proposal seeks to understand the temporal dynamics and effects of endogenous MOR signaling in the DRNEnkNAc pathway. My previous postdoctoral research, using pharmacology, genetics, and optogenetics/chemogenetics, has identified the terminals of an enkephalinergic dorsal raphe nucleus projection to NAc as the site of MOR action for modulating food intake behaviors. To better understand how MOR signaling affects this pathway, I will use two in vivo imaging approaches, fiber photometry and microendoscopy, to determine how endogenous MOR signals shape neural circuit activity during motivated behaviors (Aim 1, K99). Additionally, because the roles of specific intracellular signaling cascades have not been well defined in brain reward circuits, I will manipulate G-protein and beta-arrestin signaling pathways to determine how each of them contributes to behavior (Aim 2, K99). During the K99 phase, I will also be preparing to lead my own research lab. I will actively participate in scientific society leadership positions (chairing symposia, steering committees), learn about how to direct a lab (budgeting and administrative tasks), and continue to further my scholarly knowledgebase (planned interactions with my mentor and committee members). For the R00 “independent” phase of my proposal, I propose to build on the mentored training above to examine what mechanisms and circuits underlie MOR-mediated affective `liking' in NAc (Aim 3). These studies are of interest because growing evidence suggests that though NAc MORs can robustly modulate both motivation and affect, they likely do so via different neural mechanisms. Understanding how these biopsychological systems are dissociable, even within a specific neurochemical class, has important implications for developing novel therapeutic drugs that are efficacious without also having a propensity for abuse. I will selectively disrupt or restore MOR function using multiple genetic mouse models and viral vector interventions, as well as record endogenous neuronal responses in vivo using microendoscopic approaches. I will perform these experiments while testing mice on the affective test reactivity (TR) test, which classifies and quantifies innate orofacial reactions to taste stimuli and has been used effectively for decades to measure the affective value of taste stimuli. The knowledge gained from these studies and mentorship opportunities will greatly facilitate the development of my own research program, preparing me for the next phase of my career.