Elucidating the role of the endogenous opioid dynorphin in reward seeking

项目摘要： 本培训计划的主要目标是了解如何强啡肽调节电路中， 背内侧纹状体（DMS）增强寻求自然（蔗糖）和药物（芬太尼）奖励的行为。 强啡肽-κ阿片受体（dyn-KOR）信号传导增强和纹状体活动异常与 从消遣性寻求阿片类药物到持续性寻求阿片类药物的转变。然而，如何dyn神经元活动和随后的-KOR 纹状体的调节调节蔗糖或芬太尼寻找是未知的。在我的第一阶段 博士后研究，使用药理学，遗传学，体内光度学和光遗传学相结合，我 确定了在BLA输入端到DMS的逆行dyn传递增强了BLA-DMS活性，并促进了 自然的奖励行为。然而，当神经元的活动和释放， 奖励是未知的。因此，我将接受培训，并使用体内双光子成像来了解 DMS动力学系综如何编码蔗糖奖赏寻求（Aim 1A，K99）。我还将广泛描述 并使用一种新的DYN生物传感器，该生物传感器使用体内光度测定法来确定整体活性的模式是否 反映在随后的DMS dyn版本中（Aim 1B，K99）。此外，由于异常的dyn-KOR信号传导是 与适应不良的阿片类药物寻求有关，我的初步数据表明，dyn-KOR活性的作用，以增强 为了寻求蔗糖，我将开发和使用口服芬太尼自我管理模式，结合体内 当BLA-DMS末端在芬太尼寻找过程中被使用时，光度法进行解剖（Aim 2A，K99）。我也会 DMS中dyn或BLA中KOR的多重条件性缺失，并刺激DMS中dyn的释放， 在芬太尼寻找过程中用体内光度法确定增强的dyn-KOR信号是否负性 调节芬太尼的寻找（目标2B，K99）。对于R00 "独立"阶段的我的建议，我建议延长 在我自己的实验室里进行了目标1和2的研究。我将描述二甲基甲硫氨酸动力系统整体活动如何编码芬太尼- 寻求，操纵特定的合奏，以控制行为，通过空间光调制，并剖析必要性 DMS中的BLA输入在芬太尼寻找期间诱导dyn释放（目标3，R00）。拟议的研究 特别是解决如何提高内源性强啡肽-KOR信号，通过其控制的活动， DMS，规范天然和芬太尼奖励寻求。在建议的K99培训期间，我将接受 在体内双光子钙成像方法、阿片样物质生物传感器成像和口服自我给药中。 此外，我会积极参加科学学会会议，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（计划的互动 我的导师和委员会成员）。总而言之，这个奖项将大大促进我的发展， 我有自己的研究计划，从而为我作为一名首席研究员的独立神经科学生涯做好准备。

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.