In vivo three-photon microscopy of the cortical gray and white matter

项目摘要 多发性硬化症（MS）是一种中枢神经系统的炎性脱髓鞘疾病， 仅在美国就有近一百万人。虽然MS通常被认为是一种白色物质疾病， 在MS患者中，灰质病变负荷可能超过白色物质。 病变在灰质和白色物质病变之间不同。有趣的是，在跨越白色和灰质的病变中， 区域，显示白色病变的病理标志，表明细胞环境 明显调节少突胶质细胞的损失和再生。此外，髓鞘再生的尝试 常见于皮质与白色病变，与患者年龄或病程无关。这些发现 提示灰质区域髓鞘再生可能受到功能整合减少的特定限制 与白色区相比，新的少突胶质细胞的数量。了解区域差异， 少突胶质细胞的损失和再生代表了MS研究界中明显未满足的需求。一个主要 理解这些区域性差异的局限性是不能监测少突胶质细胞的动态 存在于活体大脑中的白色物质中。为了克服这一障碍，我们将使用新的光学方法来确定 少突胶质细胞行为的区域变异性。我们建议使用三种不同的上级穿透深度- 光子激发荧光和纵向体内成像，以确定电路特异性 神经元活性和脱髓鞘损伤对少突胶质细胞系细胞在浅表和深部的 成人大脑该建议的目标是：1）评估行为相关的神经元活动 调节灰质和白色质少突胶质细胞的发生，2）阐明行为干预是否同样可以 促进灰质和白色物质的少突胶质细胞再生。这一提议的总体假设是 少突胶质细胞前体分化和整合的区域特异性速率决定了 髓鞘形成在健康、适应性和再生环境中的作用。该提议代表了一种新的合成方法， 光学物理学和少突胶质细胞生物学的前沿方法，并在以下方面开辟了新天地： 了解灰质和白色少突胶质细胞可塑性调节的机制， 再生

PROJECT SUMMARY Multiple Sclerosis (MS) is an inflammatory, demyelinating disease of the central nervous system that afflicts nearly 1 million people in the United States alone. While MS is classically regarded as a white matter disease, gray matter lesion load may exceed that of the white matter in patients with MS. The pathological features of lesions differ between gray and white matter lesions. Interestingly, in lesions that span white and gray matter regions, display pathological hallmarks of white matter-only lesions, suggesting that cellular environments distinctly regulate oligodendrocyte loss and regeneration. Furthermore, attempts at remyelination are more frequent in cortical versus white matter lesions regardless of patient age or disease duration. These findings suggest that remyelination of gray matter regions may be specifically limited by decreased functional integration of new oligodendrocytes compared to white matter regions. Understanding the regional differences in oligodendrocyte loss and regeneration represents a clear unmet need in the MS research community. A major limitation to understanding these regional differences is the inability to monitor the dynamics of oligodendrocytes in white matter in the living brain. To overcome this obstacle, we will use new optical methodologies to determine regional variability in oligodendrocyte cell behavior. We propose to use the superior penetration depth of three- photon excitation fluorescence and longitudinal in vivo imaging to determine the effects of circuit-specific neuronal activity and demyelinating injury on oligodendrocyte lineage cells in both superficial and deep areas of the adult brain. The objectives of this proposal are: 1) evaluate how behaviorally-relevant neuronal activity regulates gray and white matter oligodendrogenesis, 2) to elucidate whether behavioral interventions can equally promote oligodendrocyte regeneration of the gray and white matter. The overall hypothesis of this proposal is region-specific rates of oligodendrocyte precursor differentiation and integration govern the proportion of myelination in healthy, adaptive, and regenerative contexts. This proposal represents a novel synthesis of cutting-edge approaches in optical physics and oligodendrocyte biology, and breaks new ground in understanding the mechanisms underlying the regulation of gray and white matter oligodendrocyte plasticity and regeneration.