The folds of the brain offer a particular challenge for the subarachnoid vascular grid. The primitive blood vessels that occupy this space, when the brain is flat, have to adapt to an everchanging geometry while constructing an efficient network. Surprisingly, the result is a non-redundant arterial system easily challenged by acute occlusions. Here, we generalize the optimal network building principles of a flat surface growing into a folded configuration and generate an ideal middle cerebral artery (MCA) configuration that can be directly compared with the normal brain anatomy. We then describe how the Sylvian fissure (the fold in which the MCA is buried) is formed during development and use our findings to account for the differences between the ideal and the actual shaping pattern of the MCA. Our results reveal that folding dynamics condition the development of arterial anastomosis yielding a network without loops and poor response to acute occlusions.

大脑的褶皱对蛛网膜下腔血管网格提出了特殊的挑战。当大脑平坦时，占据这个空间的原始血管必须适应不断变化的几何形状，同时构建有效的网络。令人惊讶的是，结果是非冗余的动脉系统很容易受到急性闭塞的挑战。在这里，我们概括了平坦表面生长为折叠配置的最佳网络构建原理，并生成了可以直接与正常大脑解剖结构进行比较的理想大脑中动脉（MCA）配置。然后，我们描述了大脑外侧裂（大脑中动脉埋藏的褶皱）在发育过程中是如何形成的，并利用我们的发现来解释大脑中动脉理想和实际成型模式之间的差异。我们的结果表明，折叠动力学决定了动脉吻合术的发展，产生了一个没有环路的网络，并且对急性闭塞的反应较差。