Department of Psychiatry, University Medical Center Utrecht, 3508 GA Utrecht, The Netherlands.
J Neurosci. 2010 Nov 24;30(47):15915-26. doi: 10.1523/JNEUROSCI.2874-10.2010.
Brain regions are not independent. They are interconnected by white matter tracts, together forming one integrative complex network. The topology of this network is crucial for efficient information integration between brain regions. Here, we demonstrate that schizophrenia involves an aberrant topology of the structural infrastructure of the brain network. Using graph theoretical analysis, complex structural brain networks of 40 schizophrenia patients and 40 human healthy controls were examined. Diffusion tensor imaging was used to reconstruct the white matter connections of the brain network, with the strength of the connections defined as the level of myelination of the tracts as measured through means of magnetization transfer ratio magnetic resonance imaging. Patients displayed a preserved overall small-world network organization, but focusing on specific brain regions and their capacity to communicate with other regions of the brain revealed significantly longer node-specific path lengths (higher L) of frontal and temporal regions, especially of bilateral inferior/superior frontal cortex and temporal pole regions. These findings suggest that schizophrenia impacts global network connectivity of frontal and temporal brain regions. Furthermore, frontal hubs of patients showed a significant reduction of betweenness centrality, suggesting a less central hub role of these regions in the overall network structure. Together, our findings suggest that schizophrenia patients have a less strongly globally integrated structural brain network with a reduced central role for key frontal hubs, resulting in a limited structural capacity to integrate information across brain regions.
大脑区域并非相互独立的。它们通过白质束相互连接，共同构成一个整合的复杂网络。这个网络的拓扑结构对于大脑区域之间的有效信息整合至关重要。在这里，我们证明精神分裂症涉及大脑网络结构基础的异常拓扑结构。我们使用图论分析方法，对 40 名精神分裂症患者和 40 名健康对照者的复杂结构大脑网络进行了研究。使用弥散张量成像来重建大脑网络的白质连接，连接的强度定义为通过磁共振成像磁化转移比测量的束的髓鞘化程度。患者表现出整体保留的小世界网络组织，但关注特定的大脑区域及其与大脑其他区域的通信能力时，发现额叶和颞叶区域的节点特定路径长度（更高的 L）明显更长，特别是双侧额下回/上回和颞极区域。这些发现表明，精神分裂症影响额叶和颞叶大脑区域的全局网络连通性。此外，患者的额叶枢纽区域的介数中心性显著降低，表明这些区域在整体网络结构中的中心枢纽作用降低。总的来说，我们的研究结果表明，精神分裂症患者的结构大脑网络整体连接强度较弱，关键的额叶枢纽区域的中心枢纽作用降低，导致跨大脑区域整合信息的结构能力受限。
