Disrupted developmental organization of the structural connectome in fetuses with corpus callosum agenesis
Disrupted developmental organization of the structural connectome in fetuses with corpus callosum agenesis
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DOI：
10.1016/j.neuroimage.2015.02.038
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发表时间：
2015-05-01
期刊：
影响因子：
5.7
通讯作者：
Langs, Georg
中科院分区：
文献类型：
--
作者：
Jakab, Andras;Kasprian, Gregor;Langs, Georg
胼胝体发育不全是人类大脑连通性中断的一种典型疾病，其中半球间纤维的病理形成导致轻微到严重的认知缺陷。产后研究表明，这种病理的特征性异常通路是通过神经可塑性出现的代偿结构。我们挑战这一假设，并假设一个全球不同的网络组织的结构相互连接已经在胎儿非异位大脑。本研究招募了20例伴有或不伴有相关畸形的孤立胼胝体发育不全的胎儿，使用子宫内弥散张量成像和流线束造影术评估了90个脑区的纤维连通性。采用多粒度网络分析方法对20例胎龄匹配的正常发育胎儿进行宏观尺度的连接体比较。妊娠期间逐渐增加的连接强度和束扩散各向异性在前后运行的顺侧和前侧运行的异常通路以及颞顶区域的短程连接中占主导地位。在有相关异常的胎儿中，与孤立的胼胝体发育不全相比，观察到更多的弥漫性皮质-皮质和皮质-皮质下连通性降低。解剖网络的整体组织由非allosal大脑中较少分离的节点组成，而密集连接的枢纽，如丘脑和扣带皮层，显示出网络中心性降低。与正常胎儿相比，非异位胎儿大脑显示出整体连接网络结构的改变。除了先前描述的Probst束和s型束外，我们还发现了一个产前不同组织的大连接组，主要是连接增加。这些发现提供的证据表明，在胎儿大脑发育的早期阶段，在大多数大脑白质中已经存在异常通路。(C) 2015爱思唯尔公司版权所有。
Agenesis of the corpus callosum is a model disease for disrupted connectivity of the human brain, in which the pathological formation of interhemispheric fibers results in subtle to severe cognitive deficits. Postnatal studies suggest that the characteristic abnormal pathways in this pathology are compensatory structures that emerge via neural plasticity. We challenge this hypothesis and assume a globally different network organization of the structural interconnections already in the fetal acallosal brain.Twenty fetuses with isolated corpus callosum agenesis with or without associated malformations were enrolled and fiber connectivity among 90 brain regions was assessed using in utero diffusion tensor imaging and streamline tractography. Macroscopic scale connectomes were compared to 20 gestational age-matched normally developing fetuses with multiple granularity of network analysis.Gradually increasing connectivity strength and tract diffusion anisotropy during gestation were dominant in antero-posteriorly running paramedian and antero-laterally running aberrant pathways, and in short-range connections in the temporoparietal regions. In fetuses with associated abnormalities, more diffuse reduction of cortico-cortical and cortico-subcortical connectivity was observed than in cases with isolated callosal agenesis. The global organization of anatomical networks consisted of less segregated nodes in acallosal brains, and hubs of dense connectivity, such as the thalamus and cingulate cortex, showed reduced network centrality.Acallosal fetal brains show a globally altered connectivity network structure compared to normals. Besides the previously described Probst and sigmoid bundles, we revealed a prenatally differently organized macroconnectome, dominated by increased connectivity. These findings provide evidence that abnormal pathways are already present during at early stages of fetal brain development in the majority of cerebral white matter. (C) 2015 Elsevier Inc. All rights reserved.