Department of Psychology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan.
PLoS One. 2012;7(10):e46970. doi: 10.1371/journal.pone.0046970. Epub 2012 Oct 9.
Knowledge of amygdalar and hippocampal development as they pertain to sex differences and laterality would help to understand not only brain development but also the relationship between brain volume and brain functions. However, few studies investigated development of these two regions, especially during infancy. The purpose of this study was to examine typical volumetric trajectories of amygdala and hippocampus from infancy to early adulthood by predicting sexual dimorphism and laterality. We performed a cross-sectional morphometric MRI study of amygdalar and hippocampal growth from 1 month to 25 years old, using 109 healthy individuals. The findings indicated significant non-linear age-related volume changes, especially during the first few years of life, in both the amygdala and hippocampus regardless of sex. The peak ages of amygdalar and hippocampal volumes came at the timing of preadolescence (9-11 years old). The female amygdala reached its peak age about one year and a half earlier than the male amygdala did. In addition, its rate of growth change decreased earlier in the females. Furthermore, both females and males displayed rightward laterality in the hippocampus, but only the males in the amygdala. The robust growth of the amygdala and hippocampus during infancy highlight the importance of this period for neural and functional development. The sex differences and laterality during development of these two regions suggest that sex-related factors such as sex hormones and functional laterality might affect brain development.
了解杏仁核和海马体的发育情况，包括它们与性别差异和侧化的关系，有助于理解不仅是大脑发育，还有大脑体积和大脑功能之间的关系。然而，很少有研究调查这两个区域的发育情况，尤其是在婴儿期。本研究的目的是通过预测性别二态性和侧化来检查杏仁核和海马体从婴儿期到成年早期的典型体积轨迹。我们对 109 名健康个体进行了横断面形态磁共振成像研究，以研究从 1 个月到 25 岁期间杏仁核和海马体的生长情况。研究结果表明，无论性别如何，杏仁核和海马体的体积都呈现出显著的非线性年龄相关变化，尤其是在生命的头几年。杏仁核和海马体体积的峰值年龄出现在青春期前（9-11 岁）。女性杏仁核的峰值年龄比男性早一年半左右，而且其生长变化的速度也较早下降。此外，女性和男性的海马体都表现出右侧偏侧化，但只有男性的杏仁体表现出右侧偏侧化。婴儿期杏仁核和海马体的强烈生长突出了这一时期对神经和功能发育的重要性。这两个区域在发育过程中的性别差异和侧化表明，与性别相关的因素，如性激素和功能侧化，可能会影响大脑发育。
