Abstract：
Rich-club organization is key to efficient global neuronal signaling and integration of information. Alterations interfere with higher-order cognitive processes, and are common to several psychiatric and neurological conditions. A few studies examining the structural connectome in obsessive-compulsive disorder (OCD) suggest lower efficiency of information transfer across the brain. However, it remains unclear whether this is due to alterations in rich-club organization. In the current study, the structural connectome of 28 unmedicated OCD patients, 8 of their unaffected siblings and 28 healthy controls was reconstructed by means of diffusion-weighted imaging and probabilistic tractography. Topological and weighted measures of rich-club organization and connectivity were computed, alongside global and nodal measures of network integration and segregation. The relationship between clinical scores and network properties was explored. Compared to healthy controls, OCD patients displayed significantly lower topological and weighted rich-club organization, allocating a smaller fraction of all connection weights to the rich-club core. Global clustering coefficient, local efficiency, and clustering of nonrich club nodes were significantly higher in OCD patients. Significant three-group differences emerged, with siblings displaying highest and lowest values in different measures. No significant correlation with any clinical score was found. Our results suggest weaker structural connectivity between rich-club nodes in OCD patients, possibly resulting in lower network integration in favor of higher network segregation. We highlight the need of looking at network-based alterations in brain organization and function when investigating the neurobiological basis of this disorder, and stimulate further research into potential familial protective factors against the development of OCD.
摘要：
丰富的俱乐部组织是有效的全球神经元信号传导和信息整合的关键。改变会干扰高阶认知过程，是常见的几种精神和神经疾病。一些研究强迫症（OCD）中结构连接组的研究表明，大脑中信息传递的效率较低。然而,目前尚不清楚这是否是由于富人俱乐部组织的改变。在目前的研究中,28名未经药物治疗的强迫症患者的结构连接体，通过扩散加权成像和概率示踪成像重建了8个未受影响的兄弟姐妹和28个健康对照。计算了丰富俱乐部组织和连通性的拓扑和加权度量，以及网络整合和隔离的全球和节点措施。探讨了临床评分与网络特性之间的关系。与健康对照相比，强迫症患者表现出明显较低的拓扑结构和加权丰富的俱乐部组织，将所有连接权重的一小部分分配给富人俱乐部核心。全局聚类系数，本地效率，在强迫症患者中，非富俱乐部节点的聚集明显更高。出现了明显的三组差异，兄弟姐妹在不同的度量中显示最高值和最低值。没有发现与任何临床评分的显著相关性。我们的结果表明，强迫症患者富俱乐部节点之间的结构连通性较弱，可能导致较低的网络集成度，而有利于较高的网络隔离。我们强调在研究这种疾病的神经生物学基础时，需要研究大脑组织和功能的基于网络的改变，并刺激进一步研究针对强迫症发展的潜在家族保护因素。
