Department of Neurosurgery, Hofstra North Shore LIJ School of Medicine, and Feinstein Institute for Medical Research, Manhasset, New York 11030, Departments of Neuroscience and.
Department of Psychology, University of Toronto, Toronto, M5S 3G3, Ontario, Canada, and.
J Neurosci. 2014 Jul 2;34(27):9152-63. doi: 10.1523/JNEUROSCI.4289-13.2014.
The cerebral cortex is composed of subregions whose functional specialization is largely determined by their incoming and outgoing connections with each other. In the present study, we asked which cortical regions can exert the greatest influence over other regions and the cortical network as a whole. Previous research on this question has relied on coarse anatomy (mapping large fiber pathways) or functional connectivity (mapping inter-regional statistical dependencies in ongoing activity). Here we combined direct electrical stimulation with recordings from the cortical surface to provide a novel insight into directed, inter-regional influence within the cerebral cortex of awake humans. These networks of directed interaction were reproducible across strength thresholds and across subjects. Directed network properties included (1) a decrease in the reciprocity of connections with distance; (2) major projector nodes (sources of influence) were found in peri-Rolandic cortex and posterior, basal and polar regions of the temporal lobe; and (3) major receiver nodes (receivers of influence) were found in anterolateral frontal, superior parietal, and superior temporal regions. Connectivity maps derived from electrical stimulation and from resting electrocorticography (ECoG) correlations showed similar spatial distributions for the same source node. However, higher-level network topology analysis revealed differences between electrical stimulation and ECoG that were partially related to the reciprocity of connections. Together, these findings inform our understanding of large-scale corticocortical influence as well as the interpretation of functional connectivity networks.
大脑皮层由子区域组成，其功能特化在很大程度上取决于它们之间的传入和传出连接。在本研究中，我们询问哪些皮层区域可以对其他区域和整个皮层网络产生最大的影响。以前关于这个问题的研究依赖于粗略的解剖结构（映射大纤维通路）或功能连接（映射持续活动中的区域间统计依赖性）。在这里，我们将直接电刺激与皮层表面的记录相结合，为清醒人类大脑皮层内的定向区域间影响提供了新的见解。这些定向相互作用的网络在强度阈值和个体之间具有可重复性。定向网络特性包括：（1）随着距离的增加，连接的互惠性降低；（2）主要投射节点（影响源）位于 Rolandic 皮层周围以及颞叶的后、基底和极区；（3）主要接收节点（影响接收器）位于额前外侧、顶叶上和颞叶上区。源自电刺激和静息脑电描记术（ECoG）相关性的连通性图谱显示出相同源节点的相似空间分布。然而，更高层次的网络拓扑分析揭示了电刺激和 ECoG 之间的差异，这些差异部分与连接的互惠性有关。这些发现共同为我们理解大尺度皮质间影响以及功能连接网络的解释提供了信息。
