Molecular mechanisms of excitatory postsynaptic diversity

兴奋性突触后多样性的分子机制

• 批准号: 10308717
• 负责人: JASON P WEICK
• 金额: $ 37.88万
• 依托单位: UNIVERSITY OF NEW MEXICO HEALTH SCIS CTR
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-01-01 至 2025-12-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10308717
• 关键词: AMPA Receptors; Active Biological Transport; Acute; Address; Affect; Affective; Animals; Behavior; Behavioral; Brain; Cell surface; Cells; Chronic; Cultured Cells; Data; Dendritic Spines; Development; Elements; Excitatory Synapse; Family; Family member; Gene Family; Genes; Glutamates; Goals; Hippocampus (Brain); Image; In Vitro; Individual; Integral Membrane Protein; Knock-out; Knockout Mice; Knowledge; Label; Long-Term Potentiation; Maintenance; Mental Depression; Molecular; Molecular Profiling; Morphology; Motor; Neurons; Pathway interactions; Pattern; Physiological; Play; Population; Post-Translational Protein Processing; Preparation; Presynaptic Terminals; Process; Property; Proteins; Proteome; Publishing; Regulation; Role; Scaffolding Protein; Second Messenger Systems; Shapes; Signaling Protein; Site; Slice; Stimulus; Surface; Synapses; Techniques; Time; Vesicle; Work; anxiety-like behavior; base; behavior test; cognitive function; density; ex vivo imaging; experience; fear memory; information processing; knockout animal; member; nerve supply; neural network; novel; overexpression; postsynaptic; postsynaptic neurons; protein expression; protein transport; recruit; response; subcellular targeting; synaptic function; trafficking

Unique patterns of synaptic connectivity between neurons, and the differential strength of those synapses, are fundamental to the information processing capability of the brain. Synaptic strength is determine by the number, composition, and post-translational modifications of post-synaptic AMPA receptors (AMPARs). These features of AMPARs are regulated by a host of second messenger pathways, scaffolding proteins, and trafficking proteins in post-synaptic densities (PSDs). For synapses that display primarily postsynaptic plasticity, the proteins responsible for regulating AMPAR surface expression are thought to be shared across glutamatergic PSDs. Thus, it remains unknown whether fundamental differences in synaptic strength between synapses exist due to unique protein signatures of individual PSDs. Neuron-specific genes (NSG1-3) encode single transmembrane proteins involved in the secretory trafficking of multiple scaffold and signaling proteins, including postsynaptic AMPARs. Studies in cultured cells as well as acute hippocampal slice preparations have established that disrupting NSG1-3 function independently causes severe alterations in basal synaptic activity and plasticity. Interestingly, our published and preliminary evidence show that NSG1 and NSG2 chronically reside within a subset of synapses in excitatory hippocampal neurons. In addition, our data show that knockout (KO) of these proteins differentially affects network function and induces behavioral deficits. This study will be significant because it will identify whether multiple members of the NSG family are restricted to a unique subpopulation of excitatory synapses, and confer unique functional properties via the promotion of AMPAR surface expression. We will use a combination of validated and novel techniques to address these important questions in three specific aims: Specific Aim 1. Determine whether NSG proteins define unique population(s) of excitatory synapses. We will use in vitro time lapse, and ex vivo imaging to determine whether NSG1 and NSG2 are specifically targeted to a subset of hippocampal synapses or trafficked between them. Specific Aim 2. Determine whether individual NSG proteins differentially affect synaptic function. Using physiological recordings and glutamate uncaging we will determine whether NSG1/2 are differentially involved in promoting surface AMPAR expression during basal or activity-dependent conditions. Specific Aim 3: Determine whether KO of NSG proteins leads to specific, dissociable behavioral deficits. Using established and novel behavioral tests in single and double KO mice we will determine whether NSG1/2 proteins play unique or overlapping roles in shaping motor, affective, and cognitive function in live animals.

神经元之间突触连接的独特模式，以及这些突触的不同强度， 是大脑信息处理能力的基础。突触的强度由数量决定， 组成和突触后AMPA受体（AMPAR）的翻译后修饰。这些特征 的AMPAR受第二信使途径、支架蛋白和运输蛋白的调节 突触后密度（PSD）。对于主要显示突触后可塑性的突触， 负责调节AMPAR表面表达的基因被认为是跨突触能PSD共享的。 因此，仍然不知道突触之间的突触强度是否存在根本差异， 独特的蛋白质特征。神经元特异性基因（NSG 1 -3）编码单跨膜 参与多种支架和信号蛋白的分泌运输的蛋白质，包括突触后 AMPAR。对培养细胞以及急性海马切片制备物的研究已经确定， 破坏NSG 1 -3功能独立地引起基础突触活性和可塑性的严重改变。 有趣的是，我们发表的和初步的证据表明，NSG 1和NSG 2长期存在于一个细胞内， 兴奋性海马神经元中突触的子集。此外，我们的数据显示，敲除（KO）这些 蛋白质差异地影响网络功能并诱导行为缺陷。这项研究将具有重要意义 因为它将确定NSG家族的多个成员是否仅限于一个独特的亚群， 兴奋性突触，并通过促进AMPAR表面表达赋予独特的功能特性。 我们将结合使用经过验证的新技术，从三个方面来解决这些重要问题。 具体目标： 具体目标1。确定NSG蛋白是否定义了兴奋性突触的独特群体。 我们将使用体外时间推移和离体成像来确定NSG 1和NSG 2是否特异性地被 以海马突触的子集为目标或在它们之间进行交易。 具体目标2。确定是否个别NSG蛋白质差异影响突触功能。 使用生理记录和谷氨酸释放，我们将确定NSG 1/2是否与正常对照组差异。 在基础或活性依赖性条件下参与促进表面AMPAR表达。 具体目标3：确定NSG蛋白的KO是否导致特异性的、可分离的行为缺陷。 在单基因敲除小鼠和双基因敲除小鼠中使用已建立的和新的行为测试，我们将确定NSG 1/2 蛋白质在形成活动物的运动、情感和认知功能中发挥独特或重叠的作用。