Imaging Neuronal and Capillary Dysfunction Deep in the Rodent Brain in vivo Using 1700 NM Optical Coherence Microscopy and Tracer-Based Kinetics

摘要： 皮质下病理是衰老、阿尔茨海默病和血管性痴呆的共同特征，但一直以来 在体内用微米分辨率进行研究是极其困难的。光学方法，如双光子显微镜 将浅层皮质成像在微米级，但这些传统显微镜方法的分辨率 超过600微米的成像深度会迅速退化。标准全脑磁共振成像 核磁共振成像(MRI)方法还不能提供细胞级别的分辨率，而且实施起来往往很昂贵。因此，在那里 迫切需要一种方法来直接评估深皮质和皮质下的血流灌注和细胞损伤 微观层面，从而弥合了现有的表面光学显微镜和宏观之间的差距 成像。这项提议将开发和应用新的光学成像技术和配套方法 直接研究遗传学中皮质下(海马区和白质)细胞和血管的变化 小鼠的疾病模型，不需要转基因表达荧光蛋白。我们建议 开发和验证在单个毛细管水平上量化通过时间分布的方法；将这些方法结合起来 用方法测量神经细胞活性、髓鞘形成、斑块分布、萎缩；最后， 阿尔茨海默病模型小鼠大脑皮质和海马区深部损伤的时间进程 疾病可达2毫米的深度。这些技术将在临床前实验中产生广泛的影响 在治疗学和生物标记物发现方面的研究，并将推动脑白质损伤和 皮质下痴呆症。这里提出的初步开发、验证和演示将催化 广泛采用这些新技术来非侵入性地研究皮层下的病理生理学 老鼠的大脑。

Abstract: Subcortical pathology is a common feature in aging, Alzheimer's disease and vascular dementia but has been extremely difficult to study with micron resolution in vivo. Optical methods such as two-photon microscopy image the superficial cortex at the micron-scale, but the resolution of these conventional microscopic methods degrades rapidly beyond 600 microns imaging depth. Standard whole-brain magnetic resonance imaging (MRI) methods do not yet provide cellular-level resolution and are often expensive to implement. Thus, there is a pressing need for methods to directly assess deep cortical and subcortical perfusion and cellular injury at the microscopic level, thus bridging the gap between existing superficial optical microscopy and macroscopic imaging. This proposal will develop and apply novel optical imaging technologies and accompanying methods to directly investigate subcortical (hippocampal and white matter) cellular and vascular changes in genetic mouse models of disease, without the need for transgenic expression of fluorescent proteins. We propose to develop and validate methods to quantify transit time distribution at the single capillary level; combine these with methods to measure neuronal cell viability, myelination, plaque distribution, atrophy; and finally, to longitudinally image the time course of deep cortical and hippocampal injury in a mouse model of Alzheimer's disease up to a depth of 2 mm. These techniques will have a widespread impact in preclinical experimental research in therapeutics and biomarker discovery, and will advance the study of white matter injury and subcortical dementia. The initial development, validation, and demonstration proposed here will catalyze the widespread adoption of these novel techniques to study subcortical pathophysiology non-invasively in the mouse brain.