Impact of fentanyl dependence on a parabrachio-amygdalar opioid circuit

项目摘要/摘要 阿片使用障碍仍然是一个可怕的公共卫生问题，但阿片激动剂，如芬太尼，仍然是第一个- 针对几种疼痛情况的直线治疗。在娱乐使用环境中，长期使用阿片类激动剂止痛 管理可能会产生身体依赖，并导致疼痛阈值和耐受性的矛盾下降， 这增加了患者对阿片类药物的依赖，并增加了过渡到阿片类药物使用障碍的可能性。 持续刺激抑制性阿片受体(MOR)，它是止痛剂和 阿片激动剂的奖赏效应，诱导逆适应性兴奋过程和超兴奋性 表达MOR的神经元。发现利用阿片类药物的益处但减轻厌恶情绪的新疗法 和长期使用阿片类药物的威胁生命的副作用，关键是确定特定的细胞类型和 大脑中易受阿片类药物诱导的细胞适应不良影响的神经回路 依赖和OIH。MORS在整个上升疼痛通路中都有密集表达，包括在 桥臂旁核(PBNMOR)。PBNMOR神经元投射到中央被膜区 杏仁核，其本身包含一组表达蛋白激酶C-δ的前伤害感受性神经元 (CECPKCδ)激活PBNMOR®CEC通路降低疼痛耐受性并增加厌恶相关 反应，但它在推动OIH和戒断中的作用，特别是CeCPKCδ神经元的贡献，已经 没有被调查过。该提案的目标是确定芬太尼依赖对神经的影响。 PbNMOR®CeCPKCδ通路的活性，以及这种活性是否会驱动戒断和OIH相关行为。 目的1研究芬太尼依赖对PBNMOR®CEC投射的影响及其在驾驶中的作用 应用体内群体钙成像和化学发生操作研究OIH与戒断行为 在伤害性测试和戒断过程中。目标2将成像和操作CECPKCδ种群在 以确定其在OIH和戒断中的贡献。这些目标的成功实现将为 为今后阿片类药物依赖的病理生理学研究奠定基础。理想情况下，这项工作的结果 将为减少特定细胞类型内的依赖机制提供新的治疗途径。女士。 伍尔德里奇将接受化学遗传学、体内钙成像及其分析、病毒介导的专家培训 基因靶向，以及严格的实验设计和统计。增加这项培训将有助于 申请者当前和未来的研究目标，并使她能够对基础神经科学产生持续的影响 在未来的职业生涯中，作为一名独立的学术研究人员进行研究。

Project Summary/Abstract Opioid Use Disorder remains a dire public health problem, but opioid agonists such as fentanyl remain a first- line therapy for several pain conditions. As in recreational use settings, prolonged use of opioid agonists in pain management can produce physical dependence and a paradoxical decrease in pain thresholds and tolerance, which increase patients’ reliance on opioids and increase the likelihood of transitioning to Opioid Use Disorder. Continual stimulation of the inhibitory µ-opioid receptor (MOR), the primary mediator of the analgesic and rewarding effects of opioid agonists, induces counter-adaptive excitatory processes and hyperexcitability in MOR-expressing neurons. To discover new treatments that leverage the benefits of opioids but mitigate aversive and life-threatening side effects of prolonged opioid use, it is critical to determine the specific cell-types and neural circuits in the brain that are susceptible to the opioid-induced cellular maladaptations that underlie dependence and OIH. MORs are densely expressed throughout ascending pain pathways, including in the parabrachial nucleus of the pons (PBNMOR). PBNMOR neurons project to the capsular region of the central amygdala (CeC), which itself contains a pronociceptive population of neurons expressing Protein Kinase C-δ (CeCPKCδ) Activation of the PBNMOR®CeC pathway decreases pain tolerance and increases aversion-related responses, but its role in driving OIH and withdrawal, and the contribution of CeCPKCδ neurons in particular, has not been investigated. The goal of the proposal is to determine the impact of fentanyl dependence on the neural activity in the PBNMOR®CeCPKCδ pathway and whether such activity drives withdrawal and OIH-related behaviors. Aim 1 will investigate the effects of fentanyl dependence on PBNMOR®CeC projections and their role in driving OIH and withdrawal behavior by using in vivo population calcium imaging and chemogenetic manipulations during nociceptive assays and withdrawal. Aim 2 will image and manipulate the CeCPKCδ population during behavior to determine its contribution to OIH and withdrawal. Successful completion of these Aims will lay the foundation for future investigations of the pathophysiology of opioid dependence. Ideally, results from this work will suggest novel therapeutic avenues for reducing dependence mechanisms within specific cell-types. Ms. Wooldridge will receive expert training in chemogenetics, in vivo calcium imaging and its analysis, viral-mediated genetic targeting, and rigorous experimental design and statistics. The addition of this training will facilitate the applicant’s current and future research goals and enable her to have continual impact on basic neuroscience research throughout a future career as an independent academic researcher.