Graduate School of Informatics and Engineering, University of Electro-Communications, Tokyo, Japan.
Department of Functional Brain Imaging, National Institutes for Quantum Science and Technology, Chiba, Japan.
J Cereb Blood Flow Metab. 2023 Jun;43(6):1010-1024. doi: 10.1177/0271678X231156372. Epub 2023 Feb 8.
Brain capillaries play a crucial role in maintaining cellular viability and thus preventing neurodegeneration. The aim of this study was to characterize the brain capillary morphology at rest and during neural activation based on a big data analysis from three-dimensional microangiography. Neurovascular responses were measured using a genetic calcium sensor expressed in neurons and microangiography with two-photon microscopy, while neural acivity was modulated by stimulation of contralateral whiskers or by a seizure evoked by kainic acid. For whisker stimulation, 84% of the capillary sites showed no detectable diameter change. The remaining 10% and 6% were dilated and constricted, respectively. Significant differences were observed for capillaries in the diameter at rest between the locations of dilation and constriction. Even the seizures resulted in 44% of the capillaries having no detectable change in diameter, while 56% of the capillaries dilated. The extent of dilation was dependent on the diameter at rest. In conclusion, big data analysis on brain capillary morphology has identified at least two types of capillary states: capillaries with diameters that are relatively large at rest and stable over time regardless of neural activity and capillaries whose diameters are relatively small at rest and vary according to neural activity.
脑毛细血管在维持细胞活力方面起着至关重要的作用，从而防止神经退行性变。本研究的目的是基于三维微血管造影的大数据分析，描述静息状态和神经激活时的脑毛细血管形态。使用在神经元中表达的遗传钙传感器和双光子显微镜进行微血管反应测量，同时通过对侧胡须刺激或通过海人酸诱发的癫痫发作来调节神经活性。对于胡须刺激，84%的毛细血管部位没有检测到直径变化。其余的 10%和 6%分别扩张和收缩。在静息时的直径方面，扩张和收缩部位的毛细血管存在显著差异。即使癫痫发作也导致 44%的毛细血管直径没有检测到变化，而 56%的毛细血管扩张。扩张的程度取决于静息时的直径。总之，对脑毛细血管形态的大数据分析已经确定了至少两种类型的毛细血管状态：静息时直径相对较大且不受神经活动影响的毛细血管和静息时直径相对较小且根据神经活动而变化的毛细血管。
