Optogenetic approaches to study post-stroke recovery mechanisms

研究中风后恢复机制的光遗传学方法

• 批准号: 9288239
• 负责人: GARY K STEINBERG
• 金额: $ 55.27万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-01 至 2020-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9288239
• 关键词: 3-Dimensional; Acute; Address; Affect; Animals; Area; Automobile Driving; Bilateral; Brain; Brain imaging; Cause of Death; Cells; Cerebellum; Clinical Research; Cognition; Data; Dentate nucleus; Equilibrium; Exhibits; Functional Magnetic Resonance Imaging; Future; Global Change; Glutamates; Goals; Grant; Imaging Techniques; Infarction; Investigation; Label; Limb structure; Molecular Analysis; Motor; Motor Cortex; Mus; Neuroglia; Neurologic; Neurological outcome; Neuronal Plasticity; Neurons; Oligodendroglia; Optics; Patients; Permeability; Phase; Publications; Recovery; Recovery of Function; Reporter; Resolution; Role; Scanning; Side; Site; Staining method; Stains; Stroke; Structure; Synapses; Techniques; Therapeutic; Time; Tracer; Transcranial magnetic stimulation; Transgenic Organisms; Visuospatial; axonal sprouting; behavior test; cell type; design; disability; effective therapy; excitatory neuron; finger movement; imaging study; improved; in vivo; inhibitory neuron; insight; limb movement; millisecond; neural circuit; neuron loss; neurotrophic factor; neurotropin; optogenetics; post stroke; public health relevance; relating to nervous system; stroke recovery; tool

 DESCRIPTION (provided by applicant): Stroke is a major acute neurological insult that disrupts brain function and causes neuron death. Recovery of lost function can occur after stroke and is attributed to brain reorganization and neuroplasticity. In this proposal, we will use optogenetics and imaging techniques to study brain circuit dynamics and axonal plasticity during post-stroke recovery. Optogenetics allows activation or inhibition of specific cell groups and circuits in the brain with millisecond-scale precision, thus is a valuable tool for studying neural circuits involved in post-stroke recovery. We recently demonstrated that selective neuronal stimulation in the ipsilesional motor cortex (iM1) using optogenetics can activate plasticity mechanisms and promote recovery. In Aim 1 we will use optogenetic functional MRI (ofMRI) to study global changes in brain circuit activation evoked by selective optogenetic stimulations during post-stroke recovery in non-stimulated stroke mice and repeatedly-stimulated stroke mice. In Aim 2A we will examine brain circuit activation at the cellular level in 3-D whole brain using two lines of activity reporter mice: neuronal activation reporter mice (FosTRAP) and synaptic activity reporter mice (ArcTRAP). We will determine the cell type of these activated neurons (excitatory vs inhibitory). In Aim 2B we will investigate how stimulations alter structural plasticity through axonal sprouting using the anterograde tracer (biotinylated-labeled dextranamine). The CLARITY technique will be used for Aim 2 to visualize cellular resolution of circuit activities and axonal sprouting in 3-D whole brains. In Aim 3 we will use the optogenetics technique to determine the role of the contralesional cortex (side opposite to stroke) during post-stroke recovery. Some studies indicate that contralesional cortex activation is necessary for recovery, whereas other studies suggest that contralesional cortex activation may be maladaptive and worsen recovery. To determine whether the contralesional cortex exerts beneficial or deleterious effects during recovery and whether there is a time-dependent role, we will manipulate specific neural circuits in the contralesional cortex at different post- stroke phases (early vs late) and examine their effects on functional recovery. Functional recovery will be evaluated by a panel of sensorimotor behavior tests that are well established in our lab. Activity-dependent neurotrophin expression and structural plasticity (axonal sprouting) will be examined in the groups that exhibit functional recovery. Our findings will advance the understanding of neural circuits and brain reorganization during post-stroke recovery.

 描述（由申请人提供）：中风是一种主要的急性神经损伤，会破坏大脑功能并导致神经元死亡。中风后可以恢复失去的功能，这归因于大脑重组和神经可塑性。在本提案中，我们将使用 光遗传学和成像技术研究中风后恢复期间的脑回路动力学和轴突可塑性。光遗传学可以以毫秒级的精度激活或抑制大脑中的特定细胞群和电路，因此是研究神经元的宝贵工具。 参与中风后恢复的电路。我们最近证明，使用光遗传学对同侧运动皮层（iM1）进行选择性神经元刺激可以激活可塑性机制并促进恢复。在目标 1 中，我们将使用光遗传学功能 MRI (ofMRI) 来研究非刺激中风小鼠和反复刺激中风小鼠在中风后恢复过程中选择性光遗传学刺激引起的脑回路激活的整体变化。在目标 2A 中，我们将使用两种活动报告小鼠系在 3-D 全脑的细胞水平上检查脑回路激活：神经元激活报告小鼠 (FosTRAP) 和突触活动报告小鼠 (ArcTRAP)。我们将确定这些激活神经元的细胞类型（兴奋性与抑制性）。在目标 2B 中，我们将研究刺激如何改变结构 使用顺行示踪剂（生物素标记的右旋糖胺）通过轴突萌芽可塑性。 CLARITY 技术将用于 Aim 2，以可视化 3D 全脑中回路活动和轴突萌芽的细胞分辨率。在目标 3 中，我们将使用光遗传学技术来确定对侧皮层（与中风相反的一侧）在中风后恢复过程中的作用。一些研究表明对侧皮层激活对于恢复是必要的，而其他研究表明对侧皮层激活可能会产生适应不良并使恢复恶化。为了确定对侧皮质在恢复过程中是否发挥有益或有害作用以及是否存在时间依赖性作用，我们将在中风后的不同阶段（早期与晚期）操纵对侧皮质中的特定神经回路，并检查它们对功能恢复的影响。功能恢复将通过我们实验室完善的感觉运动行为测试小组进行评估。将在表现出功能恢复的组中检查活动依赖性神经营养素表达和结构可塑性（轴突发芽）。我们的研究结果将增进对中风后恢复期间神经回路和大脑重组的理解。