Department of Mechanical Engineering and Intelligent System, University of Electro-Communications, Tokyo, Japan.
Department of Functional Brain Imaging, National Institute of Radiological Sciences, Chiba, Japan.
Adv Exp Med Biol. 2021;1269:323-327. doi: 10.1007/978-3-030-48238-1_51.
The present study describes methodological aspects of image analysis for angiographic image data with long-term two-photon microscopy acquired for the investigation of dynamic changes in the three-dimensional (3D) network structure of the capillaries (less than 8 μm in diameter) in the mouse cerebral cortex. Volume images of the identical capillaries over different periods of days up to 32 days were compared for adaptation under either chronic hypoxia (8-9% O) or hyperoxia (40-50% O). We observed that the median diameters of measured capillaries were 5.8, 8.4, 9.0, and 8.4 μm at 0, 1, 2, and 3 weeks during exposure to hypoxia, respectively (N = 1, n = 2193 pairs at day 0), and 5.4, 5.7, 5.4, 6.0, and 6.1 μm measured weekly up to 32 days under hyperoxia (N = 1, n = 1025 pairs at day 0). In accordance with these changes in capillary diameters, tissue space was also observed to change in a depth-dependent manner under hypoxia, but not hyperoxia. The present methods provide us with a method to quantitatively determine three-dimensional vascular and tissue morphology with the aid of a computer-assisted graphical user interface, which facilitates morphometric analysis of the cerebral microvasculature and its correlation with the adaptation of brain cells imaged simultaneously with the microvasculature.
本研究描述了一种用于分析长期双光子显微镜获取的血管造影图像数据的方法学，这些图像数据用于研究小鼠大脑皮层中毛细血管（直径小于 8μm）的三维（3D）网络结构的动态变化。将在慢性低氧（8-9% O2）或高氧（40-50% O2）环境下不同天数（最多 32 天）获得的相同毛细血管的体积图像进行比较，以观察适应情况。我们观察到，在低氧暴露期间，分别在第 0、1、2 和 3 周测量的毛细血管的中位数直径为 5.8、8.4、9.0 和 8.4μm（N=1，n=2193 对，第 0 天），而在高氧暴露下，每周测量的毛细血管直径分别为 5.4、5.7、5.4、6.0 和 6.1μm（N=1，n=1025 对，第 0 天）。与这些毛细血管直径的变化一致，组织空间也被观察到在低氧环境下以深度依赖的方式发生变化，但在高氧环境下没有发生变化。本方法为我们提供了一种借助计算机辅助图形用户界面定量确定三维血管和组织形态的方法，有助于对大脑微血管及其与同时成像的脑细胞适应的相关性进行形态计量学分析。
