DISSECTING DYNORPHIN-KAPPA OPIOID MEDIATED REINSTATEMENT OF NICOTINE PREFERENCE

尽管最近努力控制使用，尼古丁的使用仍处于历史最高水平，每年造成数百万人死亡。 并且仍然是最难停止使用的药物之一。虽然有许多关于阿片受体的报道，特别是 κ-阿片受体依赖性调节觅药，目前仍有少数研究探讨这一回路 应激诱导的内源性阿片肽/受体活性对自然奖赏和尼古丁的作用机制 复职在我们的第一个R01周期中，我们确定基底外侧杏仁核内的KOR， 海马体和延髓核神经元参与尼古丁位置偏好和恢复。在 最近的R37周期，我们在我们以前的工作基础上，开发了小鼠尼古丁自我给药， 可以使用几种先进的方法来评估电路功能。在这里，我们提出并决定，虽然我们的 主要候选人，BNST KOR不需要恢复尼古丁寻求。然后我们同时转向 系统地检查其他应激敏感的阿片肽和受体表达区域，包括背侧 和腹侧纹状体，BLA，臂旁核和屏状核，以确定在哪里 强啡肽/KOR回路参与调节、增强和恢复奖赏寻求行为。证据 我们之前的周期，强烈表明杏仁核（BLA），背侧纹状体，背侧核和屏状核是 在可能的关键位点介导阿片类药物的影响，包括KOR对压力诱导的奖励寻求。 然而，虽然我们将这些区域隔离为对各种压力和奖励寻求行为重要的区域， 成分，特定的细胞类型，回路动力学，可塑性，以及这些回路在奖励中的时间作用 然而，尼古丁IVSA仍然是未知的。在这个周期中，我们建议系统地剖析如何激活 KOR，通过应激诱导的内源性阿片样物质释放，阿片肽的光遗传学/化学遗传学调节 选择性阿片受体激动剂的释放、病毒CRISPR或全身性施用，导致改变的天然免疫应答。 奖励寻求（行动-结果）模型和IVSA小鼠模型中尼古丁寻求的恢复 兴奋性BLA至BNST回路。我们提出以下目的：1）确定强啡肽/KOR活性在 BLA-Striatal/Accumbens回路是必要的-足以调节压力诱导的奖励寻求， 使用逆行病毒拯救恢复尼古丁自我给药（"功能获得"），体内药理学， 和条件小鼠遗传学; 2）使用光遗传学和体内1p/2p钙成像，以确定如何在小鼠体内1p/2p钙成像。 这些回路中的强啡肽和KOR被应激激活并调节奖赏寻求行为 尼古丁自我给药（IVSA）模型，确定是否需要在BLA-纹状体回路中的KOR/强啡肽 压力诱导的尼古丁IVSA恢复。这些研究验证了我们的核心假设，即压力诱导的 尼古丁寻求的恢复是通过离散细胞，受体， 和电路。 相关性（参见说明）： 压力具有保护和激励成分，但反复无法控制的压力暴露会增加风险 情绪障碍和药物滥用，包括阿片类药物和尼古丁。美国烟草相关死亡人数超过40万 这些影响的生物学机制需要探索，以提供治疗方法 治疗尼古丁成瘾大脑中阿片样物质系统的激活已被证明可以编码焦虑和焦虑。 压力的焦虑效应，调节奖励并导致复发，因此拟议研究的结果将 对确定压力如何调节奖赏产生直接影响，并为尼古丁提供新的治疗策略 成瘾

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. While there are many reports of opioid receptor, specifically Kappa-opioid receptor dependent regulation of drug-seeking, there are are still few studies examining the circuit mechanisms of stress-induced endogenous opioid peptide/receptor activity on natural reward and nicotine reinstatement. In our first R01 cycle we determined that KORs within the basolateral amgydala, the CA1 of hippocampus, and nucleus accumbens neurons are involved in nicotine place preference and reinstatement. In the recent R37 cycle, we built substantially on our prior work, developing nicotine self-administration in mice so that we can use several cutting-edge methods to assess circuit function. Here we proposed and determined that while our lead candidate, BNST KORs were not required to reinstate nicotine seeking. We then in parallel turned to methodically examining, other stress-sensitive, opioid peptide and receptor expressing regions including the dorsal and ventral striatum, the BLA, the parabrachial nucleus, and the claustrum in order to determine where dynorphin/KOR circuits are engaged to regulate, potentiate and reinstate reward seeking behaviors. Evidence from our prior cycle, strongly suggests that amygdalar (BLA), dorsal striatum, nucleus accumbens and claustrum are among the likely critical loci mediating the effects of opioids, including KOR on stress induced reward seeking. However, while we isolated these regions as important for a variety of stress and reward seeking behavioral components, the specific cell types, circuit dynamics, plasticity, and the temporal role of these circuits in reward regulation, and nicotine IVSA is still not known. In this cycle we propose to methodically dissect how activation of KOR, either by stress-induced endogenous opioid release, optogenetic/chemogenetic modulation of opioid peptide release, viral CRISPR, or systemic administration of a selective opioid receptor agonists, results in altered natural reward seeking (action-outcome) models and in reinstatement of nicotine seeking in IVSA mouse models in an excitatory BLA to BNST circuit. We propose the following Aims: 1) determine the role of dynorphin/KOR activity in BLA-Striatal/Accumbens circuits as necessary - sufficient for regulating stress-induced reward seeking and reinstatement of nicotine self-administration using retrograde viral rescue (“gain of function”), in vivo pharmacology, and conditional mouse genetics; 2) Use optogenetics and in vivo 1p/2p calcium imaging, to determine the how dynorphin and KOR in these circuits are activated by stress and regulate reward seeking behaviors 3) Using a mouse model of nicotine self-administration (IVSA), determine if KOR/Dynorphin in the BLA-striatal circuits are 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 cells, receptors, and circuits. RELEVANCE (See instructions): Stress has protective and motivational components yet repeated uncontrollable stress exposure increases the risks for mood disorders and drug abuse, including opioids and nicotine. Tobacco related deaths top 400,000 in US annually and the biological mechanisms underlying these effects need to be explored in order to provide treatments for nicotine addiction. Activation of the opioid systems in brain has been shown to encode the dysphoric and anxiogenic effects of stress, regulates reward and causes relapse, so the outcomes of the proposed studies would have direct impact on determining how stress modulates reward and offer novel therapeutic strategies for nicotine addiction.