Functional roles of endogenous opioid peptides in hippocampal circuitry

项目摘要 阿片类药物有效地控制整个大脑的神经回路。产生的内源性阿片肽（EO）， 由神经元包装和释放的，在这些通路中作为效应物被突触释放。执行干事， 即强啡肽和脑啡肽，与外源性阿片样物质作用于相同的受体， 靶向细胞并抑制神经递质释放。强啡肽和脑啡肽的密集表达 在20世纪70年代首次认识到，但内源性的功能特征 由于可用的工具有限，这些肽的释放被证明是困难的。因此，EO在以下方面的作用 突触和电路动力学仍不清楚。此外，阿片肽能系统经历了戏剧性的 癫痫发生的改变，因此强调需要了解EOs如何影响神经元回路 内稳态并导致无序的网络动态。 我的长期目标是研究EO信号的生理学，以及它如何有助于癫痫电路。 拟议的实验将利用小鼠遗传学，切片生理学和新的生物传感器技术， 询问健康和患病海马体中EO释放的影响。在目标1中，我将描述 两个月后，强啡肽和脑啡肽信号在苔藓纤维-CA3突触的突触前和突触后作用 靶细胞类型：中间神经元和锥体细胞。同时，我会想象阿片类药物的释放， 表征海马回路内的时空动态。在目标2中，我将研究 强啡肽和脑啡肽信号在海马过度兴奋中的功能作用通过药理学 诱导脑片的过度兴奋，我将剖析脑啡肽和强啡肽的作用， 急性过度兴奋回路中的通路。然后，使用癫痫小鼠模型，我还将研究其影响 在永久重新排列的电路中的EO信令。最后，我将分析促或抗惊厥作用的 在体内癫痫易感性模型中诱发EO释放。这项工作将是第一批探索 选择性释放EO肽在海马突触，并可能提供有关治疗的见解 癫痫中的潜在癫痫。进行这些实验的训练将培养我的科学能力 通过密切的指导与高度积极的教师，以及课程，以支持我的发展， 稿件撰写、排版和表达能力。我会熟练掌握假设 开发和实验设计，同时增加我在突触生理学，电路， 研究和转化科学。同时，我将在学术界培养领导力和教学技能， 医学，以及我的社区，以获得成为一名优秀的临床科学家所必需的素质。

Project Summary Opioids potently control neuronal circuitry throughout the brain. Endogenous opioid peptides (EOs), produced, packaged, and released by neurons, are synaptically released as the effectors in these pathways. EOs, namely dynorphin and enkephalin, act at the same receptors as exogenous opioids, often by hyperpolarizing target cells and inhibiting neurotransmitter release. The dense expression of dynorphin and enkephalin throughout the hippocampus was first recognized in the 1970s, but functional characterization of endogenous release of these peptides proved difficult due to the limited tools available. As a result, the role of EOs in synaptic and circuit dynamics remains unclear. Furthermore, the opioid peptidergic system undergoes dramatic alterations in epileptogenesis, thus underscoring the need to understand how EOs affect neuronal circuit homeostasis and contribute to disordered network dynamics. My long term goal is to examine the physiology of EO signaling and how it may contribute to epileptic circuits. The proposed experiments will utilize mouse genetics, slice physiology, and novel biosensor technology to interrogate the effects of EO release in the healthy and diseased hippocampus. In Aim 1, I will characterize the pre- and postsynaptic effects of dynorphin and enkephalin signaling at the mossy fiber-CA3 synapse at two target cell types: interneurons and pyramidal cells. Simultaneously, I will visualize opioid release to characterize the spatiotemporal dynamics within the hippocampal circuit. In Aim 2, I will investigate the functional role of dynorphin and enkephalin signaling in hippocampal hyperexcitability. By pharmacologically inducing hyperexcitability in brain slices, I will dissect the roles of enkephalinergic and dynorphinergic pathways in the acutely hyperexcitable circuit. Then, using epileptic mouse models, I will also study the effects of EO signaling in the permanently rearranged circuit. Finally, I will assay the pro- or anti-convulsant effects of evoked EO release in an in vivo seizure susceptibility model. This work will be among the first to explore selective release of EO peptides at hippocampal synapses, and may provide insight regarding the therapeutic potential of EOs in epilepsy. The training to carry out these experiments will develop my scientific competency through close mentorships with highly motivated faculty, as well as coursework to support my development in manuscript writing, grantsmanship, and presentation ability. I will develop proficiency in hypothesis development and experimental design while growing my fund of knowledge in synaptic physiology, circuit research, and translational science. In tandem, I will cultivate leadership and teaching skills within academic medicine, as well as my community, to garner the qualities necessary to be an excellent clinician-scientist.