Individual variability in the nonlinear development of the corpus callosum during infancy and toddlerhood: a longitudinal MRI analysis
Individual variability in the nonlinear development of the corpus callosum during infancy and toddlerhood: a longitudinal MRI analysis
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婴儿期和幼儿期胼胝体非线性发育的个体差异：纵向 MRI 分析
DOI：
10.1007/s00429-022-02485-y
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发表时间：
2022
影响因子：
3.1
通讯作者：
F.
中科院分区：
文献类型：
--
作者：
Tsuzuki;D.;Taga;G.;Watanabe;H.;& Homae;F.
人类的大脑需要几年的时间，通过内在和外在的调节来引导自己，从而逐渐发展空间组织和功能。基于以往对胼胝体（CC）发育模式和个体间变异的研究，我们假设婴儿胼胝体形状的内在变化，取决于胼胝体在发育时间轴上的位置。本研究利用婴儿期至幼儿期的纵向磁共振成像数据，应用多层模型研究了CC正中矢状面面积、厚度和形状。采用Procrustes方法提取形状特征。我们发现了CC发展中的非线性、区域依赖性、个体间变异性以及个体内部一致性。总体而言，第一年的生长速度比第二年快，而且不同婴儿的生长轨迹不同；个别婴儿的CC形成方向在6个月内确定并保持到2岁。前亚区和后亚区面积和厚度的增加比其他亚区快。此外，我们澄清了一些个体CC中部的生长速度在第二年比第一年快。由于表现出不同倾向的区域的划分与先前报道的基于构成该区域的轴突直径的划分一致，我们的结果表明，亚区域依赖的个体差异是由于轴突直径的增加而发生的，髓鞘形成部分是由于早期发育时期的经验和轴突消除。
The human brain spends several years bootstrapping itself through intrinsic and extrinsic modulation, thus gradually developing both spatial organization and functions. Based on previous studies on developmental patterns and inter-individual variability of the corpus callosum (CC), we hypothesized that inherent variations of CC shape among infants emerge, depending on the position within the CC, along the developmental timeline. Here we used longitudinal magnetic resonance imaging data from infancy to toddlerhood and investigated the area, thickness, and shape of the midsagittal plane of the CC by applying multilevel modeling. The shape characteristics were extracted using the Procrustes method. We found nonlinearity, region-dependency, and inter-individual variability, as well as intra-individual consistencies, in CC development. Overall, the growth rate is faster in the first year than in the second year, and the trajectory differs between infants; the direction of CC formation in individual infants was determined within six months and maintained to two years. The anterior and posterior subregions increase in area and thickness faster than other subregions. Moreover, we clarified that the growth rate of the middle part of the CC is faster in the second year than in the first year in some individuals. Since the division of regions exhibiting different tendencies coincides with previously reported divisions based on the diameter of axons that make up the region, our results suggest that subregion-dependent individual variability occurs due to the increase in the diameter of the axon caliber, myelination partly due to experience and axon elimination during the early developmental period.