Functional roles of endogenous opioid peptides in hippocampal circuitry

内源性阿片肽在海马回路中的功能作用

• 批准号: 10604826
• 负责人: Natasha Warikoo
• 金额: $ 4.77万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-04-01 至 2026-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10604826
• 关键词: Acute; Adult; Affect; Analgesics; Anticonvulsants; Attenuated; Behavior; Binding; Biological Assay; Biosensor; Brain; Cells; Characteristics; Communities; Competence; Complement; Data; Development; Disease; Drug Modulation; Dynorphins; Educational process of instructing; Electrophysiology (science); Enkephalins; Epilepsy; Epileptogenesis; Experimental Designs; Faculty; Fluorescence; Funding; Future; GTP-Binding Proteins; Goals; Hippocampus; Homeostasis; Inhibitory Synapse; Interneurons; Kainic Acid; Knowledge; Lead; Leadership; Ligands; Light; Manuscripts; Measures; Mediating; Medicine; Mentorship; Modeling; Mus; Neurons; Opioid; Opioid Peptide; Opioid Receptor; Pain; Pathway interactions; Pentylenetetrazole; Peptide Signal Sequences; Peptides; Performance; Pharmaceutical Preparations; Pharmacogenetics; Physiologic pulse; Physiology; Potassium; Predisposition; Probability; Property; Pyramidal Cells; Research; Rewards; Role; Scientist; Seizures; Signal Transduction; Slice; Specificity; Stimulus; Synapses; System; Technology; Therapeutic; Time; Training; Translational Research; Viral; Visualization; Whole-Cell Recordings; Work; Writing; abuse liability; brain tissue; cell type; designer receptors exclusively activated by designer drugs; endogenous opioids; epileptiform; experimental study; granule cell; improved; in vitro Assay; in vivo; insight; light effects; mossy fiber; mouse genetics; mouse model; neural circuit; neuronal circuitry; neuronal excitability; neurotransmitter release; novel; optogenetics; patch clamp; pharmacologic; postsynaptic; presynaptic; receptor; response; selective expression; skills; spatiotemporal; tool; transmission process

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.

项目摘要 阿片类药物有效控制整个大脑的神经元电路。内源性阿片类肽（EOS），产生， 包装并由神经元释放，在这些途径中作为效应子释放。 EOS， 即强啡肽和ankephalin，与外源阿片类药物相同的受体作用，通常是通过超极化 靶细胞并抑制神经递质释放。多啡肽和enkephalin的致密表达 整个海马首先在1970年代被认可，但内源性的功能表征 由于可用的工具有限，这些肽的释放被证明很困难。结果，EOS在 突触和电路动力学尚不清楚。此外，阿片类肽肽系统发生戏剧性 癫痫发生的改变，因此强调了了解EOS如何影响神经元电路的需求 体内平衡并导致网络动态无序。 我的长期目标是检查EO信号传导的生理学及其如何促进癫痫电路。 提出的实验将利用小鼠遗传学，切片生理和新型生物传感器技术来 询问EO释放在健康和患病的海马中的影响。在AIM 1中，我将表征 在苔藓纤维-CA3突触处的测能和ankephalin信号传导的突触前和突触后作用在两个 靶细胞类型：中间神经元和锥体细胞。同时，我将可视化阿片类药物的释放 表征海马电路内的时空动力学。在AIM 2中，我将调查 测能和烯酚信号传导在海马过度刺激性中的功能作用。通过药理学 诱导大脑切片过度刺激性，我将剖析脑肾上腺素和源能的作用 急性过度的电路中的途径。然后，使用癫痫小鼠模型，我还将研究效果 永久重新排列的电路中的EO信号传导。最后，我将测定 在体内癫痫发作易感模型中诱发了EO释放。这项工作将是第一个探索的人之一 选择性释放在海马突触处的EO肽，并可能提供有关治疗性的见解 EOS在癫痫中的潜力。进行这些实验的培训将发展我的科学能力 通过与高度积极进取的教师的亲密指导，以及支持我的发展的课程 手稿写作，赠款和演示能力。我将提高假设的熟练程度 开发和实验设计，同时增加我的突触生理知识资金，电路 研究和翻译科学。同时，我将在学术中培养领导和教学技能 医学以及我的社区，以获得成为出色的临床医生所必需的品质。