Synaptic mechanisms of functional recovery after stroke

中风后功能恢复的突触机制

• 批准号: 10640995
• 负责人: Martin Hruska
• 金额: $ 29.29万
• 依托单位: WEST VIRGINIA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-08 至 2025-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10640995
• 关键词: Architecture; Behavioral; Behavioral Paradigm; Brain; Centers of Research Excellence; DLG4 gene; Data; Dendritic Spines; Ephrin-B3; Exhibits; Glutamate Receptor; Image; Individual; Knockout Mice; Link; Maps; Modification; Molecular; Mus; N-Methylaspartate; Pathology; Phase; Play; Recovery; Recovery of Function; Research; Resolution; Role; Sensorimotor functions; Signal Transduction; Site; Somatosensory Cortex; Stroke; Synapses; Synaptic Transmission; Synaptic plasticity; Testing; Universities; Vertebral column; West Virginia; Work; functional improvement; functional plasticity; hippocampal pyramidal neuron; improved; insight; mouse model; nanoarchitecture; nanoscale; new therapeutic target; novel; post stroke; postsynaptic; presynaptic; prevent; scaffold; stroke intervention; stroke model; stroke patient; stroke recovery; two-photon

Remapping of function after stroke relies on the rewiring of cortical circuitry. These structural modifications of circuits likely depend on nanoscale alteration in the molecular architecture of individual synapses that generate alternate connectivity and strengthen surviving contacts. NMDA- and AMPA-type glutamate receptors play critical roles in regulating structural and functional plasticity of synapses. Following a stroke, the signaling via AMPARsand NMDARs changes, likely due to changes in their nanoscale localization. The small size of synapses has prevented us from understanding how synaptic nano-architecture is altered by stroke and how nanoscale synaptic changes might lead to functional recovery, limiting our ability to target synapses for stroke intervention. Our proposal seeks to break down this barrier by combining state-of-the-art STEDsuper-resolution imaging with behavioral analyses of sensorimotor function in the mouse model of stroke. Our preliminary data indicate that AMPARsand NMDARs exhibit distinct organizational principles relative to spine size and presynaptic release sites, suggesting that the exact set of nanoscale rules governs synaptic transmission and plasticity. We will test the hypothesis that precise nanoscale remodeling of individual spine synapses underlies the functional recovery after stroke. In aim 1, we will determine how changes in pre- and post-synaptic nano-architecture on cortical pyramidal neurons are linked to functional recovery after stroke. By imaging the organization of scaffolding (PSD-95 and Bassoon) and functional (AMPARs, NMDARs, Munc-13) components of synapses in early and late phases of recovery after stroke, we will establish how changes in synaptic nano-architecture relate to the recovery of sensorimotor function in both young and old mice. In aim 2, we will determine the role of ephrin-B3 on the remodeling of spine nano-architecture on cortical pyramidal neurons during stroke recovery. Testing ephrin-B3 null mice in sensorimotor behavioral paradigms, we will determine whether ephrin-B3 is required for the functional recovery after stroke. Finally, using two-photon and STEDimaging of dendritic spines in the somatosensory cortex, we will determine whether ephrin-B3 regulates synaptic remodeling after stroke. Novel molecular insights gained from this research will improve our understanding of stroke pathology while providing mechanistic underpinnings into functional recovery.

中风后功能的重新映射依赖于皮质电路的重新布线。这些结构性的 电路的修改可能取决于个体分子结构的纳米级改变 产生替代连接并加强幸存接触的突触。 NMDA 和 AMPA 型 谷氨酸受体在调节突触的结构和功能可塑性中发挥着关键作用。 中风后，通过 AMPAR 和 NMDAR 的信号发生变化，可能是由于它们的变化 纳米级定位。突触的小尺寸使我们无法理解突触是如何 纳米结构因中风而改变，以及纳米级突触变化如何导致功能性改变 恢复，限制了我们针对突触进行中风干预的能力。我们的提议旨在打破 通过将最先进的 STED 超分辨率成像与行为分析相结合来克服这一障碍 中风小鼠模型中的感觉运动功能。我们的初步数据表明 AMPAR 和 NMDAR 表现出与脊柱大小和突触前释放位点相关的独特组织原则， 表明一组精确的纳米级规则控制着突触传递和可塑性。我们将 检验以下假设：单个脊柱突触的精确纳米级重塑是 中风后的功能恢复。在目标 1 中，我们将确定突触前和突触后的变化如何 皮质锥体神经元的纳米结构与中风后的功能恢复有关。通过成像 脚手架（PSD-95 和巴松管）和功能性（AMPAR、NMDAR、Munc-13）的组织 突触的组成部分在中风后恢复的早期和晚期阶段，我们将确定如何变化 突触纳米结构与年轻和年老小鼠感觉运动功能的恢复有关。 在目标2中，我们将确定肝配蛋白-B3在皮质上脊柱纳米结构重塑中的作用 中风恢复期间的锥体神经元。测试 ephrin-B3 缺失小鼠的感觉运动行为 范例，我们将确定中风后功能恢复是否需要 ephrin-B3。 最后，利用体感皮层树突棘的双光子和 STED 成像，我们将 确定 ephrin-B3 是否调节中风后突触重塑。新颖的分子见解 这项研究的成果将提高我们对中风病理学的理解，同时提供 功能恢复的机械基础。