Longitudinal Development of Human Brain Wiring Continues from Childhood into Adulthood
Longitudinal Development of Human Brain Wiring Continues from Childhood into Adulthood
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DOI：
10.1523/jneurosci.5302-10.2011
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发表时间：
2011-07-27
影响因子：
5.3
通讯作者：
Beaulieu, Christian
中科院分区：
文献类型：
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作者：
Lebel, Catherine;Beaulieu, Christian
健康的人类大脑发育是一个复杂的过程，在儿童和青少年时期持续进行，正如许多横向和纵向研究所证明的那样。然而，这些变化是否在青春期结束尚不清楚。我们使用弥散张量纤维束成像检查了103名5-32岁的健康受试者的纵向白色物质成熟;每个志愿者至少扫描两次，共扫描221次。分数各向异性（FA）和平均扩散率（MD），参数指示因素，包括髓鞘和轴突密度，在10个主要的白色物质束进行了评估。所有的道表现出显着的非线性发展轨迹FA和MD。在绝大多数儿童和青少年早期发生了显著的受试者内变化，这些变化大多在青春期后期完成投射和连合束。然而，关联道表现出青少年期后的主体内成熟的FA和MD。扩散参数的变化主要是由于垂直扩散率下降，虽然增加平行扩散率有助于长期增加FA在联合道。体积随年龄的增长显着增加大多数道，纵向措施也表现出postadolescent体积增加，在几个协会道。由于体积增加与扫描之间FA升高或MD降低无直接关系，观察到的弥散参数变化可能反映了脑白色物质束的显微结构成熟，而不仅仅是大体解剖结构。
Healthy human brain development is a complex process that continues during childhood and adolescence, as demonstrated by many cross-sectional and several longitudinal studies. However, whether these changes end in adolescence is not clear. We examined longitudinal white matter maturation using diffusion tensor tractography in 103 healthy subjects aged 5-32 years; each volunteer was scanned at least twice, with 221 total scans. Fractional anisotropy (FA) and mean diffusivity (MD), parameters indicative of factors including myelination and axon density, were assessed in 10 major white matter tracts. All tracts showed significant nonlinear development trajectories for FA and MD. Significant within-subject changes occurred in the vast majority of children and early adolescents, and these changes were mostly complete by late adolescence for projection and commissural tracts. However, association tracts demonstrated postadolescent within-subject maturation of both FA and MD. Diffusion parameter changes were due primarily to decreasing perpendicular diffusivity, although increasing parallel diffusivity contributed to the prolonged increases of FA in association tracts. Volume increased significantly with age for most tracts, and longitudinal measures also demonstrated postadolescent volume increases in several association tracts. As volume increases were not directly associated with either elevated FA or reduced MD between scans, the observed diffusion parameter changes likely reflect microstructural maturation of brain white matter tracts rather than just gross anatomy.