Multimodal Imaging and Connectome Analysis Lab, McConnell Brain Imaging Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada.
Department of Psychiatry, University of Cambridge, Cambridge, United Kingdom.
Elife. 2019 Nov 14;8:e50482. doi: 10.7554/eLife.50482.
We studied an accelerated longitudinal cohort of adolescents and young adults (n = 234, two time points) to investigate dynamic reconfigurations in myeloarchitecture. Intracortical profiles were generated using magnetization transfer (MT) data, a myelin-sensitive magnetic resonance imaging contrast. Mixed-effect models of depth specific intracortical profiles demonstrated two separate processes i) overall increases in MT, and ii) flattening of the MT profile related to enhanced signal in mid-to-deeper layers, especially in heteromodal and unimodal association cortices. This development was independent of morphological changes. Enhanced MT in mid-to-deeper layers was found to spatially co-localise specifically with gene expression markers of oligodendrocytes. Interregional covariance analysis revealed that these intracortical changes contributed to a gradual differentiation of higher-order from lower-order systems. Depth-dependent trajectories of intracortical myeloarchitectural development contribute to the maturation of structural hierarchies in the human neocortex, providing a model for adolescent development that bridges microstructural and macroscopic scales of brain organisation.
我们研究了一个加速的青少年和年轻人纵向队列（n=234，两个时间点），以调查骨髓架构的动态重新配置。使用磁化传递（MT）数据（一种对髓磷脂敏感的磁共振成像对比）生成皮质内轮廓。皮质内轮廓的混合效应模型显示了两个独立的过程：i）MT 的整体增加，以及 ii）与中到深层信号增强相关的 MT 轮廓变平，特别是在异模态和单模态联合皮质中。这种发展与形态变化无关。在中到深层发现增强的 MT 与少突胶质细胞的基因表达标记物特异性空间共存。区域间协方差分析显示，这些皮质内变化有助于高级系统与低级系统的逐渐分化。皮质内髓鞘架构发育的深度依赖性轨迹有助于人类新皮层结构层次的成熟，为连接大脑组织的微观结构和宏观尺度的青少年发育提供了模型。
