Molecular mechanisms of excitatory postsynaptic diversity

兴奋性突触后多样性的分子机制

• 批准号: 10542808
• 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/10542808
• 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; Disparate; Elements; Excitatory Synapse; Family; Family member; Gene Family; Genes; Glutamates; Goals; Hippocampus; 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; Synaptic plasticity; Techniques; Time; Vesicle; Work; anxiety-like behavior; behavior test; cognitive function; ex vivo imaging; experience; fear memory; information processing; knockout animal; member; nerve supply; neural network; novel; outcome disparities; overexpression; postsynaptic; postsynaptic neurons; protein expression; protein transport; receptor expression; 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.

神经元和这些突触的差异强度之间的突触连通性的独特模式是 大脑信息处理能力的基础。突触强度由数字确定 突触后AMPA受体（AMPARS）的组成和翻译后修饰。这些功能 AMPAR由许多第二信使途径，脚手架蛋白和运输蛋白调节 在突触后密度（PSD）中。对于主要显示突触后可塑性的突触，蛋白质 负责调节AMPAR表面表达的负责在谷氨酸能PSD中共享。 因此，尚不清楚是否由于 单个PSD的独特蛋白质特征。神经元特异性基因（NSG1-3）编码单跨膜 参与多个支架和信号蛋白的分泌贩运涉及的蛋白质，包括突触后 ampars。培养细胞以及急性海马切片制剂的研究已经确定 独立破坏NSG1-3功能会导致基础突触活性和可塑性的严重改变。 有趣的是，我们已发表的初步证据表明，NSG1和NSG2长期存在于 兴奋性海马神经元突触的子集。此外，我们的数据表明这些淘汰赛（KO） 蛋白质会差异地影响网络功能并引起行为缺陷。这项研究将是重要的 因为它将确定NSG家族的多个成员是否仅限于 兴奋性突触，并通过促进AMPAR表面表达来赋予独特的功能特性。 我们将使用经过验证和新颖技术的组合来解决这些重要问题。 具体目的： 特定目的1。确定NSG蛋白是否定义了兴奋性突触的独特种群。 我们将使用体外时间流逝，而离体成像来确定NSG1和NSG2是否具体 针对海马突触的子集或它们之间的贩运。 具体目标2。确定单个NSG蛋白是否会差异地影响突触功能。 使用生理记录和谷氨酸渗透我们将确定NSG1/2是否差异化 参与基础或活性依赖性条件下促进表面AMPAR表达。 特定目标3：确定NSG蛋白的KO是否导致特定的，可分离的行为缺陷。 使用在单一和双KO小鼠中建立的新型行为测试，我们将确定NSG1/2是否是否 蛋白质在活动物中塑造运动，情感和认知功能中起独特或重叠的作用。