OPTOGENETIC MAPPING OF CELL SPECIFIC CONNECTIONS IN THE MOUSE BRAIN AFTER STROKE

中风后小鼠大脑中细胞特异性连接的光遗传学图谱

• 批准号: 9661800
• 负责人: ADAM Q BAUER
• 金额: $ 44.06万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-30 至 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9661800
• 关键词: Adult; Affect; Anatomy; Animal Model; Area; Automobile Driving; Axon; Behavioral; Biological Markers; Brain; Brain region; Cells; Complement; Contralateral; Data; Distant; Evolution; Exhibits; Functional Magnetic Resonance Imaging; Genes; Global Change; Goals; Growth Associated Protein 43; Growth Cones; Image; Impairment; Incidence; Individual; Infarction; Injury; Integral Membrane Protein; Ischemia; Ischemic Stroke; Knockout Mice; Knowledge; Left; Maps; Measures; Molecular; Motor; Motor Cortex; Mus; Neuronal Plasticity; Optics; Pathway interactions; Patients; Pattern; Physical therapy; Population; Prevalence; Process; Proteins; Recovery; Recovery of Function; Rehabilitation therapy; Reporting; Rest; Role; Signal Transduction; Site; Stimulus; Stroke; Structure; Synapses; System; Technology; Testing; Time; Tissues; United States; Vertebral column; awake; axon growth; axonal sprouting; behavior influence; brain repair; density; disability; experience; functional restoration; human model; improved; in vivo; ischemic lesion; knock-down; motor recovery; neurobehavioral; neuroimaging; optogenetics; overexpression; relating to nervous system; repaired; restoration; stroke recovery; stroke survivor; therapeutic target; transcriptome

PROJECT SUMMARY/ABSTRACT The goal of the current proposal is to determine how molecular- and systems-level mechanisms of brain repair interact to influence behavioral recovery after focal ischemia in mice. Stroke causes direct structural damage to local circuits and indirect functional damage to global networks that can result in behavioral deficits spanning multiple domains. Neuroplasticity after stroke involves molecular changes within perilesional tissue that can be influenced by distant regions spared from injury. At the systems level, functional magnetic resonance imaging has revealed that recovery from stroke is associated with functional reorganization of the brain through the formation of new or alternative circuits. Directly impacted brain regions remap to adjacent tissue in concert with behavioral recovery. More globally, patterns of resting-state functional connectivity gradually normalize in patients experiencing good recovery. While functional neuroimaging studies in humans and animal models consistently demonstrate local and global changes in functional brain organization after stroke, it is unknown how these processes interrelate to support behavioral recovery. Understanding how (or if) remapped brain regions reintegrate into global networks to support recovery after stroke requires more direct examination of evolving local and global connectivity structure. At the molecular level, limited data suggest that new axons appear after stroke in periinfarct cortex and distant, homotopic contralateral cortex. Increased expression of plasticity-associated genes are found in perilesional tissue including those involved in axonal sprouting. Growth Associated Protein 43 (GAP-43) is an integral membrane protein found in axonal growth cones, synapses, and widely induced after focal ischemia. This protein might drive anatomical connections within the periinfarct that support functional restoration after stroke. However, the role of axonal sprouting in functional neuroplasticity following focal ischemia has not been examined. We hypothesize that GAP-43-dependent axonal sprouting is required for local circuit repair and reintegration into global networks, and this evolving process drives the degree of behavioral recovery after stroke. We further hypothesize that axonal sprouting can be modulated by neural activity in excitatory nodes functionally-connected to the site of injury, and these activity-dependent processes depend on GAP-43. Critical barriers to testing this hypothesis in vivo have been the inability to serially examine global network connectivity as it evolves with recovery, and longitudinally examine subunits of remapped circuits as they change over time. We have overcome these barriers by integrating optical intrinsic signal imaging with optogenetics to probe local circuit connectivity more directly. We will use this technology to determine: 1) how the reemergence of local circuits and global networks relate to functional recovery following focal ischemia, 2) if GAP-43-dependent axonal sprouting is required for local and/or global motor network repair and behavioral recovery, and 3) if activity in excitatory motor nodes modulates local/global motor network repair and behavioral recovery, and if these changes rely on GAP-43.

项目概要/摘要 当前提案的目标是确定大脑修复的分子和系统级机制如何 相互作用以影响小鼠局部缺血后的行为恢复。中风会导致直接的结构性损坏 局部电路和对全球网络的间接功能损害可能导致行为缺陷 多个域。中风后的神经可塑性涉及病灶周围组织内的分子变化，这些变化可以 受到遥远地区的影响而免受伤害。在系统层面，功能磁共振成像 研究表明，中风的恢复与大脑的功能重组有关 形成新的或替代的电路。直接受影响的大脑区域重新映射到邻近组织 行为恢复。在全球范围内，静息态功能连接模式逐渐正常化 患者康复情况良好。虽然人类和动物模型的功能性神经影像研究 一致地证明中风后大脑功能组织的局部和整体变化，目前尚不清楚 这些过程如何相互关联以支持行为恢复。了解如何（或是否）重新映射大脑 各地区重新融入全球网络以支持中风后的康复需要更直接的检查 不断发展的本地和全球连接结构。在分子水平上，有限的数据表明新的轴突 中风后出现在梗塞周围皮层和远处的同位对侧皮层。表达增加 在病灶周围组织中发现了可塑性相关基因，包括那些参与轴突萌芽的基因。生长 相关蛋白 43 (GAP-43) 是一种在轴突生长锥、突触和神经细胞中发现的整合膜蛋白。 局灶性缺血后广泛诱发。这种蛋白质可能会驱动梗死周围的解剖学连接 支持中风后的功能恢复。然而，轴突出芽在功能性神经可塑性中的作用 尚未检查局灶性缺血后的情况。我们假设 GAP-43 依赖性轴突萌芽是 本地电路修复和重新融入全球网络所需，这一不断发展的过程推动了程度 中风后的行为恢复。我们进一步假设轴突萌芽可以通过神经调节 与损伤部位功能相关的兴奋性节点的活动，以及这些活动依赖的过程 取决于 GAP-43。在体内检验这一假设的关键障碍是无法连续检查 随着恢复而发展的全球网络连接，并纵向检查重新映射电路的子单元 因为它们随着时间的推移而变化。我们通过将光学本征信号成像与 光遗传学更直接地探测局部电路连接。我们将使用这项技术来确定：1）如何 局部回路和全球网络的重新出现与局灶性缺血后的功能恢复有关，2）如果 GAP-43依赖性轴突萌芽是局部和/或全局运动网络修复和行为所必需的 恢复，以及 3) 兴奋性运动节点的活动是否调节局部/全局运动网络修复和行为 恢复，如果这些改变依赖于GAP-43。