The microvasculature underlies the supply networks that support neuronal activity within heterogeneous brain regions. What are common versus heterogeneous aspects of the connectivity, density, and orientation of capillary networks? To address this, we imaged, reconstructed, and analyzed the microvasculature connectome in whole adult mice brains with sub-micrometer resolution. Graph analysis revealed common network topology across the brain that leads to a shared structural robustness against the rarefaction of vessels. Geometrical analysis, based on anatomically accurate reconstructions, uncovered a scaling law that links length density, i.e., the length of vessel per volume, with tissue-to-vessel distances. We then derive a formula that connects regional differences in metabolism to differences in length density and, further, predicts a common value of maximum tissue oxygen tension across the brain. Last, the orientation of capillaries is weakly anisotropic with the exception of a few strongly anisotropic regions; this variation can impact the interpretation of fMRI data.

微脉管系统是支持异质大脑区域内神经元活动的供应网络的基础。毛细管网络的连通性、密度和方向有哪些共同点和异质点？为了解决这个问题，我们以亚微米分辨率对整个成年小鼠大脑中的微血管连接组进行了成像、重建和分析。图分析揭示了大脑中常见的网络拓扑，这导致了针对血管稀疏的共同结构鲁棒性。基于解剖学精确重建的几何分析揭示了将长度密度（即单位体积的血管长度）与组织到血管距离联系起来的比例定律。然后，我们推导出一个公式，将新陈代谢的区域差异与长度密度的差异联系起来，并进一步预测整个大脑的最大组织氧张力的共同值。最后，除了少数强各向异性区域外，毛细管的取向是弱各向异性的；这种变化会影响功能磁共振成像数据的解释。