IDEA Lab, Department of Radiology and BRIC, University of North Carolina at Chapel Hill, NC 27599-7513, USA.
Neuroimage. 2012 Sep;62(3):1622-33. doi: 10.1016/j.neuroimage.2012.05.026. Epub 2012 May 19.
Recently, an increasing body of evidence suggests that developmental abnormalities related to schizophrenia may occur as early as the neonatal stage. Impairments of brain gray matter and wiring problems of axonal fibers are commonly suspected to be responsible for the disconnection hypothesis in schizophrenia adults, but significantly less is known in neonates. In this study, we investigated 26 neonates who were at genetic risk for schizophrenia and 26 demographically matched healthy neonates using both morphological and white matter networks to examine possible brain connectivity abnormalities. The results showed that both populations exhibited small-world network topology. Morphological network analysis indicated that the brain structural associations of the high-risk neonates tended to have globally lower efficiency, longer connection distance, and less number of hub nodes and edges with relatively higher betweenness. Subgroup analysis showed that male neonates were significantly disease-affected, while the female neonates were not. White matter network analysis, however, showed that the fiber networks were globally unaffected, although several subcortical-cortical connections had significantly less number of fibers in high-risk neonates. This study provides new lines of evidence in support of the disconnection hypothesis, reinforcing the notion that the genetic risk of schizophrenia induces alterations in both gray matter structural associations and white matter connectivity.
最近，越来越多的证据表明，与精神分裂症相关的发育异常可能早在新生儿期就已经发生。普遍认为，大脑灰质的损伤和轴突纤维的连接问题是导致成年精神分裂症患者出现连接中断假说的原因，但在新生儿中，这方面的了解要少得多。在这项研究中，我们使用形态学和白质网络研究了 26 名具有精神分裂症遗传风险的新生儿和 26 名在人口统计学上匹配的健康新生儿，以检查可能存在的大脑连接异常。结果表明，这两个群体都表现出小世界网络拓扑结构。形态网络分析表明，高危新生儿的大脑结构关联往往全局效率较低，连接距离较长，枢纽节点和边缘数量较少，而介数较高。亚组分析表明，男性新生儿受到显著影响，而女性新生儿则没有。然而，白质网络分析表明，纤维网络全局不受影响，尽管高危新生儿的一些皮质下-皮质连接的纤维数量明显较少。这项研究提供了新的证据支持连接中断假说，进一步证实了精神分裂症的遗传风险会导致灰质结构关联和白质连接的改变。
