Elucidation of Nanostructure and Function of Spontaneous GABAergic Transmission at the Inhibitory Synapse

抑制性突触自发 GABA 能传递的纳米结构和功能的阐明

• 批准号: 10750025
• 负责人: Natalie Guzikowski
• 金额: $ 3.3万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-06-01 至 2025-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10750025
• 关键词: Action Potentials; Acute; Address; Anxiety; Artemisinins; Binding; Biological Models; Brain-Derived Neurotrophic Factor; Calcium; Calcium Signaling; Categories; Competitive Binding; Data; Disease; Disease Pathway; Drosophila genus; Electron Microscopy; Electrophysiology (science); Equilibrium; Excitatory Synapse; Gene Expression; Genes; Genetic Transcription; Glutamates; Health; Hippocampus; Image; Inhibitory Synapse; Intervention; Investigation; Knowledge; Laboratories; Link; Measures; Mediating; Mental Depression; Mental disorders; Molecular; Nanostructures; Neurobiology; Neuromuscular Junction; Neurons; Pathway interactions; Pharmaceutical Preparations; Property; Regulation; Research; Role; Scaffolding Protein; Schizophrenia; Signal Pathway; Signal Transduction; Structure; Support System; Synapses; Synaptic Transmission; Testing; Visualization; Work; experience; experimental study; gamma-Aminobutyric Acid; gephyrin; inhibitory neuron; insight; neuropsychiatric disorder; neurotransmission; neurotrophic factor; novel; pharmacologic; postsynaptic; presynaptic; receptor; scaffold; segregation; small molecule; tool; transcriptome sequencing; transmission process; ultra high resolution

PROJECT SUMMARY At the excitatory synapse, a heterogenous molecular layout creates a precise pre- and post-synaptic structure that facilitates different modes of neurotransmission. The spatial segregation of neurotransmission leads to the autonomous function of spontaneous glutamate release. The investigation into the structure/function relationship at the excitatory synapse has facilitated the discovery of disease pathways and targets for psychiatric disease intervention. However, aberrant inhibitory neurotransmission is also implicated in numerous psychiatric illnesses including schizophrenia, depression, and anxiety. Despite the fundamental importance of inhibitory neurotransmission in disease, few studies have investigated the relationship between nanostructure and function at the inhibitory synapse. My preliminary data suggests a segregation of action potential dependent and spontaneous neurotransmission at central inhibitory GABAergic synapses, but how this segregation is achieved is unknown. Few studies have investigated the inhibitory structure/function relationship due to the limited tools that allow for the selective manipulation of different modes of inhibitory neurotransmission. I have generated preliminary data that a novel small molecule drug, Artemisinin, selectively dysregulates inhibitory spontaneous release as it competitively binds in the GABAAR-gephyrin binding pocket; providing a new pharmacological tool that will be utilized throughout this proposal. This project will investigate the GABAergic synapse in two-fold by elucidating the post-synaptic structure that segregates neurotransmission and how this structure leads to an autonomous function of spontaneous GABAergic transmission in homeostatic plasticity. In primary hippocampal culture, Artemisinin will be used as a tool to decrease GABAergic spontaneous release to investigate how this corresponds to nanostructure and signaling pathways. The central hypothesis is GABAergic synapses have a specific post- synaptic gephyrin scaffold and GABAAR nanostructure that facilitates an autonomous role of spontaneous neurotransmission. Aim#1 will investigate how the post-synaptic structure segregates neurotransmission using super resolution and electron microscopy to assess 1a. gephyrin clustering dynamics and 1b. GABAAR subunit localization and clustering. Aim#2 will investigate the functional pathway this nanostructure facilitates by delineating the role of spontaneous GABAergic neurotransmission in homeostatic plasticity. 2a. First downstream gene expression pathways will be assessed, specifically BDNF expression. 2b. Then how spontaneous GABAergic signaling alters calcium dynamics to trigger gene transcription pathways will be delineated. This research will elucidate the relationship between structure and function at the inhibitory synapse, ultimately providing novel insight into the regulation of synaptic strength underlying excitatory/inhibitory balance in health and disease.

项目摘要 在兴奋性突触中，异源分子布局会产生精确的前后突触后 促进神经传递模式的结构。神经传递的空间隔离 导致自动功能的自主功能的释放。对 兴奋性突触时的结构/功能关系促进了疾病途径的发现 和精神病干预的目标。但是，异常抑制性神经递质也是 涉及许多精神病，包括精神分裂症，抑郁和焦虑。尽管有 抑制性神经传递在疾病中的基本重要性，很少有研究研究 纳米结构与抑制性突触的功能之间的关系。我的初步数据表明 中枢抑制的动作潜力依赖性和自发神经传递的分离 GABA能突触，但是如何实现这种隔离是未知的。很少有研究调查 由于有限的工具，抑制性结构/功能关系允许选择性操纵 不同的抑制性神经传递模式。我已经生成了一个新颖的初步数据 分子药物，青蒿素，在竞争性结合时有选择性地调节抑制性自发释放 在Gabaar-Gephyrin结合口袋中；提供一种新的药理学工具，该工具将在整个过程中使用 这个建议。该项目将通过阐明后突触来调查两倍的GABA能突触 分离神经传递的结构以及该结构如何导致自主函数 稳态可塑性中的自发GABA能传播。在原发性海马培养中，青蒿素 将用作减少GABA能自发释放的工具，以研究这与 纳米结构和信号通路。中心假设是GABA能突触具有特定后 突触Gephyrin脚手架和Gabaar纳米结构，促进自动角色 神经传递。 AIM＃1将调查后突触后结构如何分离神经传递 使用超级分辨率和电子显微镜评估1A。 Gephyrin聚类动力学和1B。加巴尔 亚基定位和聚类。 AIM＃2将研究该纳米结构的功能途径 通过描述自发GABA能神经传递在稳态可塑性中的作用来促进。 2a。将评估第一个下游基因表达途径，特别是BDNF表达。 2b。然后 自发的GABA能信号如何改变钙动力学触发基因转录途径 被描述。这项研究将阐明抑制性的结构与功能之间的关系 突触，最终为调节突触强度的调节提供新颖的见解 健康和疾病的兴奋/抑制平衡。