Nanoscale organization of the inhibitory synapse during synaptic plasticity

突触可塑性过程中抑制性突触的纳米级组织

• 批准号: 10064027
• 负责人: Katharine Rachel Smith
• 金额: $ 38.37万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-12-01 至 2024-10-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10064027
• 关键词: 3-Dimensional; AMPA Receptors; Acute; Animals; Architecture; Behavior; Brain; Brain Diseases; Cell Adhesion Molecules; Cognition; Computer Models; Data; Disease; Disease model; Electrophysiology (science); Equilibrium; Future; Glutamates; Goals; Growth; Imaging Techniques; Impairment; Inhibitory Synapse; Interneurons; Laboratories; Learning; Lighting; Location; Mediating; Memory; Microscopy; Modernization; Molecular; Neuraxis; Neurologic; Neurons; Output; Pathology; Phosphorylation; Play; Positioning Attribute; Regulation; Resolution; Role; Schizophrenia; Site; Slice; Stroke; Structure; Synapses; Synaptic plasticity; Techniques; Testing; Time; Work; autism spectrum disorder; functional outcomes; gephyrin; information processing; nanoscale; nervous system disorder; neuroligin 2; neuronal circuitry; neuronal excitability; neurotransmitter release; novel; novel therapeutic intervention; palmitoylation; postsynaptic; postsynaptic density protein; presynaptic; receptor; scaffold; synaptic function; synaptic inhibition; three dimensional structure

The correct balance between excitation and inhibition (E/I balance) in neuronal circuits is essential for learning and memory, cognition and behavior. Disrupted inhibition leading to elevated neuronal and circuit excitability is thought to underlie the pathology of numerous neurological disorders, therefore a comprehensive understanding of the molecular mechanisms involved in synaptic inhibition will have the potential to direct new therapeutic strategies for treating these conditions. GABAergic inhibitory synapses mediate the majority of synaptic inhibition in the central nervous system, and their plasticity controls neuronal excitability and function. The number of GABAA receptors (GABAARs) at inhibitory postsynaptic sites is a key determinant of inhibitory synapse strength and hence neuronal inhibition. Therefore defining mechanisms by which synaptic GABAARs are clustered and how they are altered in synaptic plasticity is imperative for understanding inhibition and its disruption in brain disorders. Using the versatile super-resolution imaging technique, Structured Illumination Microscopy (SIM), we find that GABAARs and their scaffold, gephyrin, form nanoscale subsynaptic domains (SSDs) in the inhibitory postsynaptic domain, are modulated during plasticity, and form closely associated pairs with presynaptic release SSDs in the active zone, suggesting that a modular nanoscale architecture for the inhibitory synapse may be important for their plasticity and function. Our goal is to determine the mechanisms that control inhibitory nanoscale organization, understand how this organization influences inhibitory synaptic function and is altered during synaptic plasticity, and determine how these facets differ between diverse inhibitory synapse subtypes. This proposal will (1) determine the mechanisms underlying the formation of postsynaptic inhibitory SSDs during activity-dependent synapse growth, (2) define the mechanisms and functional relevance of postsynaptic SSD clustering opposite presynaptic release sites, and (3) examine how subcellular location and interneuron input influence inhibitory nanoscale organization. These aims will test our overarching hypothesis that inhibitory synaptic nanoscale organization underlies inhibitory synaptic strength, and its dynamic regulation is a crucial mechanism for synaptic plasticity. These proposed studies will be significant, being the first comprehensive mechanistic and functional examination of inhibitory synapse architecture at nanoscale resolution (in both culture and slice) and in real-time during short- and long-term plasticity paradigms. The widespread importance of this work is that it will greatly expand our understanding of the detailed mechanisms that control inhibitory synaptic plasticity and inhibition, which is critical for maintaining E/I balance and neuronal function. Moreover, determining the nanoscale structure of inhibitory synapses in healthy brains will pave the way for future studies in disease models to provide novel understanding of how inhibitory synapse structure, function and E/I balance are disrupted in neuropathological disorders.

神经元回路中兴奋和抑制之间的正确平衡（E/I 平衡）对于学习至关重要 以及记忆、认知和行为。抑制破坏导致神经元和回路兴奋性升高 被认为是许多神经系统疾病病理学的基础，因此需要全面的研究 对突触抑制分子机制的理解将有可能指导新的研究 治疗这些病症的治疗策略。 GABA能抑制性突触介导大部分 中枢神经系统中的突触抑制及其可塑性控制神经元的兴奋性和功能。 抑制性突触后位点的 GABAA 受体 (GABAAR) 数量是抑制性突触后的关键决定因素。 突触强度，从而抑制神经元。因此定义突触 GABAAR 的机制 聚集在一起，它们如何改变突触可塑性对于理解抑制及其作用至关重要 大脑紊乱的破坏。使用多功能超分辨率成像技术，结构照明 显微镜 (SIM)，我们发现 GABAAR 及其支架 gephyrin 形成纳米级突触亚域 （SSD）位于抑制性突触后域，在可​​塑性过程中受到调节，并形成密切相关的对 突触前释放 SSD 在活动区，表明模块化纳米级架构 抑制性突触可能对其可塑性和功能很重要。我们的目标是确定机制 控制抑制性纳米级组织，了解该组织如何影响抑制性突触 功能并在突触可塑性过程中发生改变，并确定这些方面在不同的方面之间有何不同 抑制性突触亚型。该提案将（1）确定形成的机制 活动依赖性突触生长期间的突触后抑制 SSD，(2) 定义机制和 突触后 SSD 聚类与突触前释放位点相对的功能相关性，以及 (3) 检查如何 亚细胞位置和中间神经元输入影响抑制性纳米级组织。这些目标将考验我们 总体假设是抑制性突触纳米级组织是抑制性突触强度的基础， 其动态调节是突触可塑性的重要机制。这些拟议的研究将 意义重大，是第一个对抑制性突触进行全面的机制和功能检查 纳米级分辨率（培养物和切片）以及短期和长期实时的架构 可塑性范式。这项工作的广泛重要性在于它将极大地扩展我们对 控制抑制性突触可塑性和抑制的详细机制，这对于维持突触可塑性和抑制至关重要 E/I 平衡和神经元功能。此外，确定抑制性突触的纳米级结构 健康的大脑将为未来的疾病模型研究铺平道路，从而提供关于疾病如何发生的新理解 神经病理性疾病中抑制性突触结构、功能和 E/I 平衡被破坏。