DISSECTING DYNORPHIN-KAPPA OPIOID MEDIATED REINSTATEMENT OF NICOTINE PREFERENCE

Kappa阿片受体(KOR)在人类中的激活引起烦躁不安，激动剂或通过 应激诱导的强啡肽在啮齿类动物中的释放导致重新找寻药物。尽管最近做出了努力 遏制尼古丁的使用，尼古丁的使用量创历史新高，每年导致数百万人死亡，仍然是 最难停用的药物。强啡肽/KOR系统活性的厌恶效应已被联系起来 增加药物自我管理，而这一系统已知会导致毒品寻找的恢复(海洛因， 可卡因、酒精)。虽然有许多关于KOR依赖于对寻找毒品进行监管的报道，但仍然有 关于应激诱导的强啡肽KOR活性在尼古丁上的作用和机制的研究很少 复职。在我们之前的R01授予周期中，我们试图确定应激诱导的恢复 尼古丁偏好是通过强啡肽和KOR介导的，并绘制了关键的大脑区域 尼古丁偏爱、KOR和强啡肽介导的尼古丁恢复发生。我们决定， 孤束核、海马CA1区和伏隔核神经元参与尼古丁位置偏爱 和复职。我们还建立了小鼠尼古丁自我给药的恢复模型，即 依赖KOR。然而，负责KOR依赖尼古丁恢复的神经网络、动力学和电路机制尚不清楚。了解强啡肽能神经回路和 Kor原因尼古丁恢复提供有价值和重要的见解和新的治疗方法 用于治疗和预防应激相关的尼古丁复发。来自我们上一个周期的有力证据 提示杏仁核(BLA)和延展杏仁核(BNST)环路是调节 朝鲜民主主义人民共和国对复职的影响。然而，虽然我们分离了这个区域很重要，但特定的细胞类型， 电路动力学、可塑性和电路在尼古丁恢复中的时间作用尚不清楚。在这个周期中 我们建议系统地剖析KOR是如何通过应激诱导的强啡肽释放， 强啡肽释放的光遗传/化学发生调节，或选择性KOR的全身给药 激动剂可恢复兴奋性BLA至BNST环路中尼古丁的位置偏爱。我们建议 使用一系列方法的以下目的：1)确定强啡肽/KOR活动在血乳酸中的作用 BNST回路是应激诱导的尼古丁偏好恢复的必要条件和充分条件 逆行病毒拯救(“功能的获得”)、体内药理学和条件小鼠遗传学；2)使用 光遗传学和体内钙成像来确定强啡肽和KOR BLA到BNST的回路 在压力和恢复期间激活；3)使用尼古丁自我给药(IVSA)的小鼠模型， 确定应激诱导的尼古丁恢复是否需要BLA-BNST回路中的KOR/强啡肽 静脉注射用药。这些研究验证了我们的中心假设，即压力诱导尼古丁寻求的恢复是 通过在离散的BLA和BNST细胞、受体和回路中动态激活强啡肽-KOR介导。

Activation of kappa opioid receptors (KOR) in humans elicits dysphoria, and KOR activation by agonists or by stress-induced dynorphin release in rodents produces reinstatement of drug seeking. Despite recent efforts to curb use, nicotine use is at an all time high, is responsible for millions of deaths each year and remains one of the most difficult drugs to stop using. The aversive effects of dynorphin/KOR system activity have been linked to increased drug self-administration, and this system is known to cause reinstatement of drug seeking (heroin, cocaine, alcohol). While many reports of KOR dependent regulation of drug-seeking exist, there are are still few studies examining the role and mechanisms of stress-induced dynorphin-KOR activity on nicotine reinstatement. In our prior R01 grant cycle we sought to determine whether stress-induced reinstatement of nicotine preference is mediated through dynorphin and KOR, and mapped the critical brain regions where nicotine preference, and KOR and dynorphin mediated nicotine reinstatement occur. We determined that the amgydala, CA1 of hippocampus, and nucleus accumbens neurons are involved in nicotine place preference and reinstatement. We also established a reinstatement model of nicotine self-administration in mice that is KOR dependent. However, the neural networks, dynamics and circuit mechanisms responsible for KOR-dependent nicotine reinstatement are not understood. Understanding how dynorphinergic neural circuits and KOR cause nicotine reinstatement provides valuable and important insights and new therapeutic approaches to the treatment and prevention of stress-related nicotine relapse. Evidence from our prior cycle strongly suggests that amygdalar (BLA) and extended amgydala (BNST) circuits are the critical loci mediating the effects of KOR on reinstatement. However, while we isolated this region as important, the specific cell types, circuit dynamics, plasticity, and the temporal role of circuit in nicotine reinstatement is not known. In this cycle we propose to methodically dissect how activation of KOR, either by stress-induced dynorphin release, optogenetic/chemogenetic modulation of dynorphin release, or systemic administration of a selective KOR agonist, results in reinstatement of nicotine place preference in an excitatory BLA to BNST circuit. We propose the following Aims using an array of approaches: 1) determine the role of dynorphin/KOR activity in a BLA to BNST circuit as necessary and sufficient for stress-induced reinstatement of nicotine preference using retrograde viral rescue (“gain of function”), in vivo pharmacology, and conditional mouse genetics; 2) Use optogenetics and in vivo calcium imaging to determine the how dynorphin and KOR+ BLA to BNST circuits are activated by stress, and during reinstatement; 3) Using a mouse model of nicotine self-administration (IVSA), determine if KOR/Dynorphin in the BLA-BNST circuit is required for stress-induced reinstatement of nicotine IVSA. These studies test our central hypothesis that stress-induced reinstatement of nicotine seeking is mediated via dynamic dynorphin-KOR activation within discrete BLA and BNST cells, receptors, and circuits.