Neural activity-dependent modulation of cortical microvascular restoration

项目摘要/摘要 血管，从动脉到毛细血管，再到小静脉，再到静脉，对基本的生理功能有贡献。 流程。然而，皮质术后微血管网络的修复和恢复的血管反应 人们对脑损伤知之甚少，包括神经元活动如何影响这些过程。一大障碍 要研究的是大脑中微血管的难以获得性以及相关的技术困难。至 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来 研究局灶性皮质损伤后微血管的形成和再生长。我们用的是轻便的 头戴式微型显微镜(“迷你显微镜”)，以动态成像血管系统和相关 具有高空间和时间分辨率的单元。我们将使用皮质损伤模型，通过应用控制 对小鼠运动皮质有中度影响。结合体内纵向微型望远镜和双光子成像， 组织学“血管绘制”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的微血管修复。我们将应用靶向光生技术 刺激兴奋性神经元和特异性抑制性神经元调节早期和早期的微血管修复 血管再生长的后期阶段。我们的指导性假设是微血管修复和重塑 皮质损伤由血管形成序列和细胞过程调节，类似于在 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 以及局灶性皮质损伤后血管再生的空间分布和血流动力学。血管网络 和血流用荧光标记的右旋糖核酸进行体内成像，以定量 测量。在目标2中，我们将确定内皮细胞在新血管萌发中的作用，以及 Tie2-Cre报告基因小鼠移植后两周内功能微血管的建立 受伤。我们还将研究星形胶质细胞和周细胞在血管再生长中的影响。在《目标3》中，我们将 检验以时间控制的方式对特定神经元类型进行光遗传刺激的假设 促进和加强损伤后修复的微血管恢复。我们还将研究是否以及如何 神经活动的靶向调节对Wnt/？连环蛋白和血管内皮生长因子信号机制的调节至关重要 用于微血管的再生长。行为测试将评估光遗传治疗的结果。我们有 强大的初步数据，支持所有目标的拟议研究的前提。拟议的研究 将促进我们对皮层微血管背后的细胞和分子机制的理解 以及神经刺激如何促进血管网络的形成。

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.