White matter maturation reshapes structural connectivity in the late developing human brain
White matter maturation reshapes structural connectivity in the late developing human brain
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DOI：
10.1073/pnas.1009073107
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发表时间：
2010-11-02
影响因子：
11.1
通讯作者：
Grant, P. E.
中科院分区：
文献类型：
--
作者：
Hagmann, P.;Sporns, O.;Grant, P. E.
从蹒跚学步到青少年后期，人类大脑中轴突投射的宏观模式在很大程度上保持不变，同时经历了戏剧性的功能修改，导致网络细化。这些功能性改变是由髓鞘形成增加、轴突直径和突触密度变化以及神经化学介质变化介导的。在这里，我们探讨的贡献，白色物质的成熟之间的年龄2和18岁之间的连接的发展，使用高b值扩散磁共振纤维束成像和连接分析。我们测量了连接效率的变化，作为沿纤维束沿着平均扩散率的倒数。我们观察到网络拓扑的特定指标的显着改进，包括节点强度和效率的显着增加沿着集群的减少。主要的结构模块和枢纽在2岁时就已经就位，并且在随后的发展中继续加强它们的轮廓。从一个子集的主题记录静息态功能磁共振成像，我们证实了结构和功能连接之间的正相关性，并观察到这种关系随着年龄的增长而加强。随着年龄的增长，结构连接的整合不断增加，分离不断减少，这表明白色物质成熟介导的网络细化促进了全球效率的提高。此外，结构和功能连接与年龄之间的相关性的加强表明，白色物质连接与其他因素相结合，如轴突直径和髓鞘厚度的差异调节，部分被逆平均扩散率捕获，在创造全脑的一致性和同步性方面发挥着越来越重要的作用。
From toddler to late teenager, the macroscopic pattern of axonal projections in the human brain remains largely unchanged while undergoing dramatic functional modifications that lead to network refinement. These functional modifications are mediated by increasing myelination and changes in axonal diameter and synaptic density, as well as changes in neurochemical mediators. Here we explore the contribution of white matter maturation to the development of connectivity between ages 2 and 18 y using high b-value diffusion MRI tractography and connectivity analysis. We measured changes in connection efficacy as the inverse of the average diffusivity along a fiber tract. We observed significant refinement in specific metrics of network topology, including a significant increase in node strength and efficiency along with a decrease in clustering. Major structural modules and hubs were in place by 2 y of age, and they continued to strengthen their profile during subsequent development. Recording resting-state functional MRI from a subset of subjects, we confirmed a positive correlation between structural and functional connectivity, and in addition observed that this relationship strengthened with age. Continuously increasing integration and decreasing segregation of structural connectivity with age suggests that network refinement mediated by white matter maturation promotes increased global efficiency. In addition, the strengthening of the correlation between structural and functional connectivity with age suggests that white matter connectivity in combination with other factors, such as differential modulation of axonal diameter and myelin thickness, that are partially captured by inverse average diffusivity, play an increasingly important role in creating brain-wide coherence and synchrony.