Department of Pediatrics, Keck School of Medicine at USC, Los Angeles, California 90027.
Division of Cancer & Blood Diseases.
J Neurosci. 2019 Oct 16;39(42):8362-8375. doi: 10.1523/JNEUROSCI.2422-18.2019. Epub 2019 Aug 23.
Children ages 9-12 years face increasing social and academic expectations that require mastery of their thoughts, emotions, and behavior. Little is known about the development of neural pathways integral to these improving capacities during the transition from childhood to adolescence. Among 234 healthy, inner-city male and female youth (species ) 9-12 years of age followed by the Columbia Center for Children's Environmental Health, we acquired diffusion tensor imaging, multiplanar chemical shift imaging, and cognitive measures requiring self-regulation. We found that increasing age was associated with increased fractional anisotropy and decreased apparent diffusion coefficient, most prominently in the frontal and cingulate cortices, striatum, thalamus, deep white matter, and cerebellum. Additionally, we found increasing age was associated with increased -acetyl-l-aspartate (NAA) in the anterior cingulate and insular cortices, and decreased NAA in posterior cingulate and parietal cortices. Age-associated changes in microstructure and neurometabolite concentrations partially mediated age-related improvements in performance on executive function tests. Together, these findings suggest that maturation of key regions within cortico-striatal-thalamo-cortical circuits subserve the emergence of improved self-regulatory capacities during the transition from childhood to adolescence. Few imaging studies of normal brain development have focused on a population of inner-city, racial/ethnic minority youth during the transition from childhood to adolescence, a period when self-regulatory capacities rapidly improve. We used DTI and MPCSI to provide unique windows into brain maturation during this developmental epoch, assessing its mediating influences on age-related improvement in performance on self-regulatory tasks. Our findings suggest that rapid maturation of cortico-striato-thalamo-cortical circuits, represented as progressive white-matter maturation (increasing FA and increasing NAA, Ch, Cr concentrations accompanying advancing age) in frontal regions and related subcortical projections and synaptic pruning (decreasing NAA, Ch, Cr, Glx) in posterior regions, support age-related improvements in executive functioning and self-regulatory capacities in youth 9-12 years of age.
9-12 岁的儿童面临着日益增加的社会和学术期望，需要掌握自己的思想、情感和行为。在从儿童期到青春期的过渡过程中，对于这些不断提高的能力所必需的神经通路的发展，人们知之甚少。在哥伦比亚儿童环境健康中心（Columbia Center for Children's Environmental Health）跟踪的 234 名健康的市中心男女青少年中，我们获得了弥散张量成像（diffusion tensor imaging）、多平面化学位移成像（multiplanar chemical shift imaging）和需要自我调节的认知测量数据。我们发现，年龄的增长与额皮质和扣带回皮质、纹状体、丘脑、深部白质和小脑等区域的分数各向异性（fractional anisotropy）增加和表观扩散系数（apparent diffusion coefficient）降低有关。此外，我们还发现年龄的增长与前扣带回和岛叶皮质中的乙酰左旋天冬氨酸（NAA）增加以及后扣带回和顶叶皮质中的 NAA 减少有关。微观结构和神经代谢物浓度与年龄相关的变化部分介导了执行功能测试中与年龄相关的表现改善。总的来说，这些发现表明，在从儿童期到青春期的过渡过程中，皮质-纹状体-丘脑-皮质回路中的关键区域的成熟支持了自我调节能力的提高。很少有关于正常大脑发育的影像学研究集中在从儿童期到青春期过渡期间的市中心、少数族裔青年人群体，而在这个时期，自我调节能力迅速提高。我们使用 DTI 和 MPCSI 为大脑在这一发育时期的成熟提供了独特的视角，评估了它对与年龄相关的自我调节任务表现改善的中介影响。我们的发现表明，皮质-纹状体-丘脑-皮质回路的快速成熟，表现为额区白质成熟（随着年龄的增长，FA 增加，NAA、Ch、Cr 浓度增加）以及相关的皮质下投射和突触修剪（NAA、Ch、Cr、Glx 减少），支持 9-12 岁青少年与年龄相关的执行功能和自我调节能力的提高。
