Optogenetic approaches to study post-stroke recovery mechanisms

研究中风后恢复机制的光遗传学方法

基本信息

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
项目类别：
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

项目摘要

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（适用提供）：中风是一种重大的急性神经损伤，可破坏大脑功能并导致神经元死亡。中风后可能发生丧失功能的恢复，并归因于脑重组和神经可塑性。在此提案中，我们将使用势恢复期间研究脑电路动力学和轴突可塑性的光遗传学和成像技术。光遗传学允许以毫秒的精度激活或抑制大脑中特定的细胞组和电路，因此是研究中性的有价值的工具冲程后恢复涉及的电路。我们最近证明，使用光遗传学在IPSILSILE运动皮层（IM1）中的选择性神经元刺激可以激活可塑性机制并促进恢复。在AIM 1中，我们将使用光遗传学功能MRI（OFMRI）研究在未刺激的中风小鼠中冲程后恢复期间选择性光遗传学刺激引起的脑电路激活的全局变化，并反复刺激了中风小鼠。 AIM 2A我们将使用两行活性报告小鼠：神经元激活记者小鼠（FOSTRAP）和突触活动报告者小鼠（ARCTRAP）检查整个大脑的细胞水平的大脑电路激活。我们将确定这些活化神经元的细胞类型（兴奋性与抑制性）。在AIM 2B中，我们将研究刺激如何改变结构使用轴突发芽的可塑性，使用顺行示踪剂（生物素化标记的右旋胺）。清晰度技术将用于AIM 2，以可视化电路活动的细胞分辨率和3-D全脑中的轴突发芽。在AIM 3中，我们将使用光遗传学技术来确定冲程后恢复过程中混凝土皮层（与中风相反）的作用。一些研究表明，混凝土皮层激活是恢复所必需的，而其他研究表明混凝土皮层激活可能是适应不良且恢复较差。为了确定混凝土皮质在恢复过程中是否会产生有益的或有害的作用，以及是否存在时间依赖性作用，我们将在不同的中风后阶段（早期vs vs vs vs vs）操纵混凝土皮层中的特定中性回路并检查其对功能恢复的影响。功能恢复将通过在我们实验室中建立的一系列感觉运动行为测试评估。活动依赖性神经营养蛋白的表达和结构可塑性（轴突发芽）将在暴露功能恢复的组中检查。我们的发现将提高对击球后恢复期间神经环节和脑重组的理解。