Neural activity-dependent modulation of cortical microvascular restoration

项目总结/摘要 血管，从动脉到毛细血管，再到小静脉，然后到静脉，有助于基本的生理功能。 流程.然而，皮层损伤后微血管网的修复和恢复的血管反应， 对脑损伤的了解很少，包括神经元活动如何影响这些过程。一个主要障碍 研究的主要障碍是大脑中微血管的可及性差以及相关的技术困难。到 为了克服这一障碍，我们建议使用我们共同开发的创新成像技术， 研究局部皮质损伤后微血管形成和再生长。我们使用了轻量级的 头戴式微型显微镜（“微型镜”），以动态地对脉管系统和相关的 具有高空间和时间分辨率的细胞。我们将使用皮质损伤模型， 对小鼠运动皮层有中度影响。结合体内纵向微型镜和双光子成像， 组织学“血管绘画”和灌注加权磁共振成像（PWI MRI），我们的目标是实现 更深入地了解皮质损伤后微血管的恢复。我们将应用靶向光遗传学 刺激兴奋性神经元和特异性抑制性神经元以调节早期和晚期微血管修复， 血管再生的晚期阶段。我们的指导假设是， 皮质损伤受血管化序列和细胞过程的调节，这些过程在 中枢神经系统发育过程中的正常血管生成。在目标1中，我们将确定时间进程 和局部皮质损伤后血管再生的空间模式和血流动力学。血管网络 和血流用荧光标记的葡聚糖可视化，用于体内成像， 测量.在目标2中，我们将确定内皮细胞在新血管发芽中的作用， 通过对Tie 2-Cre报告小鼠进行成像来建立功能性微血管， 损伤我们还将研究星形胶质细胞和周细胞在血管再生中的影响。在目标3中，我们 测试以时间控制方式对特定神经元类型的光遗传学刺激 促进和增强用于损伤后修复的微脉管系统恢复。我们还将研究是否以及如何 神经活动的靶向调节调节Wnt/β-连环蛋白和VEGF信号传导机制， 用于微血管再生。行为测试将评估光遗传学治疗的结果。我们有 强有力的初步数据，支持所有目标的拟议研究的前提。拟议研究 将促进我们对皮层微血管的细胞和分子机制的理解 以及神经刺激如何增强血管网络的形成。

Project Summary / Abstract Blood vessels, from arteries to capillaries to venules and then to veins, contribute to fundamental physiological processes. However, the vascular responses for repair and restoration of microvascular networks after cortical brain injury are poorly understood, including how neuronal activity influences these processes. A major barrier to research is the poor accessibility of micro-vessels in the brain and associated technical difficulties. To overcome this barrier, we propose to use innovative imaging technologies that we have co-developed to investigate micro-vessel formation and re-growth in response to focal cortical injury. We have used light-weight head-mounted, miniaturized microscopes (“miniscopes”) to dynamically image the vasculature and associated cells with high spatial and temporal resolution. We will use cortical injury models by applying a controlled moderate impact to the mouse motor cortex. Combining in vivo longitudinal miniscope and 2-photon imaging, histological “vessel painting” and perfusion-weighted magnetic resonance imaging (PWI MRI), we aim to achieve a deeper understanding of microvascular restoration following cortical injury. We will apply targeted optogenetic stimulation of excitatory neurons and specific inhibitory neurons to modulate microvascular repair in early and late phases of vessel re-growth. Our guiding hypothesis is that microvascular restoration and remodeling after cortical injury are regulated by vascularization sequences and cellular processes that are similarly observed in normal vasculogenesis during central nervous system development. In Aim 1, we will identify the time course and spatial pattern of vascular regrowth, and blood flow dynamics after focal cortical injury. Vascular networks and blood flow are visualized with fluorescent-labeled dextrans for in vivo imaging for quantitative measurements. In Aim 2, we will determine the role of endothelial cells in new blood vessel sprouting and the establishment of functional microvascular by imaging Tie2-Cre reporter mice during the first two weeks post- injury. We will also examine the influence of astrocytes and pericytes in vascular re-growth. In Aim 3, we will test the hypothesis that optogenetic stimulation of specific neuron types in a temporally controlled manner facilitates and enhances microvasculature restoration for post-injury repair. We will also examine if and how targeted modulation of neural activities modulate Wnt/ß-catenin and VEGF signaling mechanisms that are critical for micro-vessel re-growth. Behavioral testing will assess the outcomes of the optogenetic treatment. We have strong preliminary data that supports the premise for the proposed research for all aims. The proposed research will advance our understanding of the cellular and molecular mechanisms underlying cortical microvascular restoration and how neural stimulation enhances vascular network formation.