Elucidating the role of the endogenous opioid dynorphin in reward seeking

项目总结： 本培训计划的主要目标是了解强啡肽对脑内神经回路的调节作用。 背内侧纹状体(DMS)增强了对自然(蔗糖)和药物(芬太尼)奖励的寻求行为。 强啡肽-kappa阿片受体(Dyn-KOR)信号增强和纹状体异常活动与 从娱乐性到持久的阿片类药物寻求的过渡。然而，Dyn神经元的活动和随后的KOR 纹状体调节蔗糖或芬太尼的作用尚不清楚。在我的第一阶段 博士后研究，结合药理学、遗传学、活体光度学和光遗传学，我 发现在BLA输入到DMS的逆行Dyn传递增强了BLA-DMS的活性，并促进了 自然的寻求奖励的行为。然而，当Dyn神经元的活动和释放准确地参与 寻求奖励是未知的。因此，我将在体内接受培训，并使用双光子成像来了解 DMS Dyn合奏如何编码蔗糖的奖励寻找，(目标1A，K99)。我还将广泛地描述 并使用一种使用体内光度学的新型Dyn生物传感器来确定整体活动模式是否 反映在随后的DMS Dyn版本中(目标1B，K99)。此外，由于异常的Dyn-KOR信号是 与不适应阿片类药物的寻找有关，我的初步数据表明Dyn-KOR活动在增强 寻找蔗糖，我将开发和使用口服芬太尼自我给药范例与体内 在寻找芬太尼的过程中，当BLA-DMS终端接合时，用光度法进行解剖(目标2A，K99)。我也会 多路条件删除DMS中的dyn或BLA中的KOR，并刺激DMS中的dyn释放， 芬太尼寻找期间的体内光度法确定增强的dyn-KOR信号是否为负性 调节芬太尼寻求(目标2B，K99)。对于我的提案的R00“独立”阶段，我建议将 在我自己的实验室里，来自目标1和目标2的发现。我将描述DMS Dyn合奏活动如何编码芬太尼- 寻求、操纵特定的合奏，通过空间光调制来控制行为，并剖析其必要性 用于DMS中的BLA输入，以在寻求芬太尼期间诱导Dyn释放(Aim 3，R00)。建议进行的研究 具体解决内源性强啡肽-KOR信号如何通过其控制细胞内的活动而升高 DMS，规范自然和芬太尼的奖赏寻求。在拟议的K99培训期间，我将接受培训 体内双光子钙成像方法、阿片类生物传感器成像和口服给药。 此外，我还会积极参加科学学会的会议，获得职业发展培训 (预算和行政任务)，并继续推进我的学术知识基础(有计划的互动 与我的导师和委员会成员)。总而言之，这个奖项将极大地促进我的 自己的研究计划，从而为我作为首席研究员的独立神经科学职业生涯做好准备。

Project Summary: The primary goal of this training proposal is to understand how dynorphinergic regulation of circuits in the dorsomedial striatum (DMS) enhances seeking behaviors for natural (sucrose) and drug (fentanyl) rewards. Enhanced dynorphin-kappa opioid receptor (dyn-KOR) signaling and aberrant striatal activity is associated with the transition from recreational to persistent opioid-seeking. Yet how dyn neuron activity and subsequent -KOR modulation of the striatum regulates sucrose or fentanyl-seeking is unknown. During the first phase of my postdoctoral research, using a combination of pharmacology, genetics, in vivo photometry and optogenetics, I identified that retrograde dyn transmission at BLA inputs to the DMS enhances BLA-DMS activity, and promotes natural reward-seeking behaviors. However, when exactly dyn neuron activity and release are engaged in reward-seeking is unknown. Hence, I will obtain training in, and use in vivo two-photon imaging to understand how DMS dyn ensembles encode reward-seeking for sucrose, (Aim 1A, K99). I will also extensively characterize and use a novel dyn biosensor using in vivo photometry to determine if the pattern of ensemble activity is reflected in subsequent DMS dyn release, (Aim 1B, K99). Furthermore, because aberrant dyn-KOR signaling is linked to maladaptive opioid-seeking, and my preliminary data suggests a role for dyn-KOR activity to enhance sucrose-seeking, I will develop and use an oral fentanyl self-administration paradigm in conjunction with in vivo photometry to dissect when BLA-DMS terminals are engaged during fentanyl-seeking (Aim 2A, K99). I will also multiplex conditional deletions of dyn in the DMS, or KOR in the BLA, and stimulate dyn release in the DMS, with in vivo photometry during fentanyl-seeking to determine whether enhanced dyn-KOR signaling negatively modulates fentanyl-seeking (Aim 2B, K99). For the R00 “independent” phase of my proposal, I propose to extend the findings from Aims 1 and 2 in my own lab. I will delineate how DMS dyn ensemble activity encodes fentanyl- seeking, manipulate specific ensembles to control behavior via spatial light modulation, and dissect the necessity for BLA inputs in the DMS to induce dyn release during fentanyl-seeking (Aim 3, R00). The proposed studies specifically address how elevated endogenous dynorphin-KOR signaling, via its control of activity in the DMS, regulates natural and fentanyl reward-seeking. During the proposed K99 training period, I will be trained in in vivo two-photon calcium imaging approaches, opioid biosensor imaging and oral self-administration. Additionally, I will actively participate in scientific society conferences, obtain career development training (budgeting and administrative tasks), and continue to further my scholarly knowledge base (planned interactions with my mentor and committee members). Altogether, this award will greatly facilitate the development of my own research program, thereby preparing me for an independent neuroscience career as a principal investigator.