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.

项目总结 在兴奋性突触，不同的分子布局创造了精确的突触前和突触后 促进不同模式的神经传递的结构。神经传递的空间分离 导致自发释放谷氨酸的自主功能。对这一事件的调查 兴奋性突触的结构/功能关系促进了疾病途径的发现 以及精神疾病干预的目标。然而，异常抑制性神经传递也是 与多种精神疾病有关，包括精神分裂症、抑郁症和焦虑症。尽管 抑制性神经传递在疾病中的基本重要性，很少有研究调查 抑制性突触的纳米结构和功能之间的关系。我的初步数据显示 中枢抑制时动作电位依赖性和自发性神经传递的分离 GABA能突触，但这种分离是如何实现的尚不清楚。很少有研究调查过 由于允许选择性操作的工具有限，抑制结构/功能关系 抑制性神经传递的不同模式。我已经生成了初步数据，一部小说 分子药物青蒿素在竞争性结合时选择性地失调抑制性自发释放 在GABAAR-吉卜林结合口袋中；提供了一种新的药理工具，将在整个过程中使用 这项提议。这个项目将通过阐明突触后的方式从两个方面来研究GABA能突触 分离神经传递的结构，以及这种结构如何导致 动态平衡可塑性中的自发GABA能传递。在原代海马区培养中，青蒿素 将被用作减少GABA能自发释放的工具来研究这是如何对应的 纳米结构和信号通路。中心假说是GABA能突触有一个特定的后脑- 促进自发性自主作用的突触地卟啉支架和GABAAR纳米结构 神经传递。目标1将研究突触后结构如何分离神经传递 使用超分辨率和电子显微镜评估1a。吉卜林聚集动力学和1b。伽巴尔 亚基定位和聚类。Aim#2将研究这种纳米结构的功能途径 通过描述自发的GABA能神经传递在体内平衡可塑性中的作用而促进。 2A。首先将评估下游基因表达途径，特别是BDNF的表达。2B。然后 自发的GABA能信号如何改变钙动力学以触发基因转录途径 被描绘出来。这项研究将阐明结构和功能之间的关系在抑制 突触，最终提供了对潜在突触力量调节的新见解 健康和疾病中的兴奋/抑制平衡。