Niu Bochao, Wu Hongzhou, Li Yilu, Klugah-Brown Benjamin, Hanna George, Yao Youwang, Jing Junlin, Baig Talha Imtiaz, Xia Yang, Yao Dezhong, Biswal Bharat
The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Laboratory for Neuroinformation, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, 611731, China.
Department of Biomedical Engineering, New Jersey Institute of Technology, Newark, NJ, 07102, USA.
Brain Struct Funct. 2024 Dec 26;230(1):20. doi: 10.1007/s00429-024-02864-7.
Acute cerebral ischemia alters brain network connectivity, leading to notable increases in both anatomical and functional connectivity while observing a reduction in metabolic connectivity. However, alterations of the cerebral blood flow (CBF) based functional connectivity remain unclear. We collected continuous CBF images using laser speckle contrast imaging (LSCI) technology to monitor ischemic occlusion-reperfusion progression through occlusion of the left carotid artery. We also used a dense cortical grid atlas to construct CBF-based functional connectivity networks for hyperacute ischemic rodents. Graph theoretical analysis was used to measure network topological characteristics and construct topological connection graphs. Coactivation pattern (CAP) analysis was utilized to examine the spatiotemporal characteristics of the global network. Additionally, we measured evoked functional hyperemia and correlated it with network topologies. Network analysis indicated a significant increase in functional connectivity, global efficiency, local efficiency, small-worldness, clustering coefficient, and regional degree centrality primarily within the left ischemic intra-hemisphere, accompanied by weaker changes in the right intra-hemisphere. Inter-hemisphere networks exhibited reduced homologous connections, global efficiency, and small-worldness. CAP analysis revealed increased strength of the left negative activation brain network's state fraction of time and transition probability from equilibrium-to-imbalance states. Left network metrics declined following blood flow reperfusion. Furthermore, positive/negative correlations between barrel-evoked intensity and regional network topologies were reversed as negative/positive correlations after cerebral ischemia. These findings suggest a damaged CBF functional network mechanism following acute cerebral ischemia and a disrupted association between resting state and evoked hyperemia.
急性脑缺血会改变脑网络连通性，导致解剖学和功能连通性显著增加，同时代谢连通性降低。然而，基于脑血流量（CBF）的功能连通性改变仍不清楚。我们使用激光散斑对比成像（LSCI）技术收集连续的CBF图像，以通过阻断左颈动脉来监测缺血性闭塞-再灌注进展。我们还使用密集皮质网格图谱为超急性缺血性啮齿动物构建基于CBF的功能连通性网络。采用图论分析来测量网络拓扑特征并构建拓扑连接图。利用共激活模式（CAP）分析来检查全局网络的时空特征。此外，我们测量了诱发的功能性充血并将其与网络拓扑结构相关联。网络分析表明，主要在左缺血性脑半球内，功能连通性、全局效率、局部效率、小世界特性、聚类系数和区域度中心性显著增加，右侧脑半球的变化较弱。半球间网络的同源连接、全局效率和小世界特性降低。CAP分析显示，左负激活脑网络状态分数时间的强度以及从平衡状态到不平衡状态的转变概率增加。血流再灌注后左网络指标下降。此外，急性脑缺血后，桶状诱发强度与区域网络拓扑之间的正/负相关性反转，变为负/正相关性。这些发现表明急性脑缺血后CBF功能网络机制受损，静息状态与诱发充血之间的关联被破坏。
