Coupling of functional connectivity and regional cerebral blood flow reveals a physiological basis for network hubs of the human brain
Coupling of functional connectivity and regional cerebral blood flow reveals a physiological basis for network hubs of the human brain
复制标题
功能连接和局部脑血流的耦合揭示了人脑网络枢纽的生理基础
DOI：
10.1073/pnas.1214900110
复制
发表时间：
2013-01-29
影响因子：
11.1
通讯作者：
Yang, Yihong
中科院分区：
文献类型：
--
作者：
Liang, Xia;Zou, Qihong;Yang, Yihong
人脑功能网络包含一些连接紧密的枢纽，这些枢纽在静息和任务状态下跨区域传递信息方面起着至关重要的作用。然而，这些功能枢纽与大脑生理指标（如局部脑血流（rCBF））之间的关系仍未完全被理解。在此，我们利用血氧水平依赖和动脉自旋标记灌注对比的功能性磁共振成像数据，研究了静息状态和N - back工作记忆任务期间功能连接强度（FCS）与rCBF之间的关系。在静息状态下，识别出具有较高FCS的脑功能枢纽，主要位于默认模式网络、脑岛和视觉区域。FCS与rCBF呈现出显著的空间相关性，并且与视觉和感觉运动网络相比，这种相关性在默认模式网络（DMN；包括内侧额 - 顶叶皮质）和执行控制网络（ECN；包括外侧额 - 顶叶皮质）中更强。此外，这种关系依赖于连接距离；即，rCBF与长程枢纽的相关性比短程枢纽更强。值得注意的是，几个DMN和ECN区域表现出每单位连接强度更高的rCBF（rCBF/FCS比值）；然而，在后部视觉区域该指数较低。在工作记忆实验中，FCS - rCBF耦合以及rCBF/FCS比值在ECN和/或DMN区域受到任务负荷的调节。最后，外侧顶叶中FCS和rCBF的任务诱导变化与行为表现呈正相关。总之，我们的研究结果表明，在静息期间血液供应和脑功能拓扑结构之间紧密耦合，并且这种耦合会根据任务需求进行调节，这可能会为人脑功能连接组的生理基础提供启示。
Human brain functional networks contain a few densely connected hubs that play a vital role in transferring information across regions during resting and task states. However, the relationship of these functional hubs to measures of brain physiology, such as regional cerebral blood flow (rCBF), remains incompletely understood. Here, we used functional MRI data of blood-oxygenation-level–dependent and arterial-spin–labeling perfusion contrasts to investigate the relationship between functional connectivity strength (FCS) and rCBF during resting and an N-back working-memory task. During resting state, functional brain hubs with higher FCS were identified, primarily in the default-mode, insula, and visual regions. The FCS showed a striking spatial correlation with rCBF, and the correlation was stronger in the default-mode network (DMN; including medial frontal-parietal cortices) and executive control network (ECN; including lateral frontal-parietal cortices) compared with visual and sensorimotor networks. Moreover, the relationship was connection–distance dependent; i.e., rCBF correlated stronger with long-range hubs than short-range ones. It is notable that several DMN and ECN regions exhibited higher rCBF per unit connectivity strength (rCBF/FCS ratio); whereas, this index was lower in posterior visual areas. During the working-memory experiment, both FCS–rCBF coupling and rCBF/FCS ratio were modulated by task load in the ECN and/or DMN regions. Finally, task-induced changes of FCS and rCBF in the lateral-parietal lobe positively correlated with behavioral performance. Together, our results indicate a tight coupling between blood supply and brain functional topology during rest and its modulation in response to task demands, which may shed light on the physiological basis of human brain functional connectome.