Functional roles of endogenous opioid peptides in hippocampal circuitry

项目摘要 阿片类药物有效地控制着整个大脑的神经回路。内源性阿片肽(Eos)，产生， 被神经元包装和释放的神经元在这些通路中作为效应器被突触释放。Eos， 即强啡肽和脑啡肽，作用于与外源性阿片类药物相同的受体，通常是通过超极化 靶细胞和抑制神经递质的释放。强啡肽和脑啡肽的密集表达 整个海马体最早是在20世纪70年代被发现的，但内源性的功能表征 由于可用的工具有限，这些多肽的释放被证明是困难的。因此，Eos在这方面的作用 突触和回路的动力学仍不清楚。此外，阿片肽能系统经历了戏剧性的 癫痫发生的改变，因此强调了了解Eos如何影响神经元回路的必要性 动态平衡，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，以及它对癫痫回路的作用。 拟议中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来 询问EO在健康和患病的海马区释放的效果。在目标1中，我将描述 强啡肽和脑啡肽信号在苔藓纤维-CA3突触前和突触后的作用 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 描述海马区内的时空动态。在《目标2》中，我将调查 强啡肽和脑啡肽信号在海马超兴奋性中的功能作用。在药理学上 在脑片上诱导高兴奋性，我将剖析脑啡肽能和强啡肽能的作用 剧烈过度兴奋回路中的通路。然后，使用癫痫小鼠模型，我也将研究其影响 永久重新排列的电路中的EO信令。最后，我将分析其促进或抗惊厥的效果。 在体内癫痫易感性模型中诱发EO释放。这项工作将是最早探索的工作之一 在海马突触选择性释放EO多肽，并可能为治疗提供洞察力 嗜酸性粒细胞在癫痫中的潜能。进行这些实验的训练将提高我的科学能力 通过与积极进取的教职员工的密切指导，以及支持我在 手稿写作能力、文笔能力和表达能力。我会精通假设 开发和实验设计，同时增加我在突触生理学、电路方面的知识 研究和翻译科学。同时，我将在学术领域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医生和科学家所必需的品质。

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.