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Abstract：
Already during the last trimester of gestation, functional responses are recorded in foetuses and preterm newborns, attesting an already complex cerebral architecture. Then throughout childhood, anatomical connections are further refined but at different rates and over asynchronous periods across functional networks. Concurrently, infants gradually achieve new psychomotor and cognitive skills. Only the recent use of non-invasive techniques such as magnetic resonance imaging (MRI) and magneto- and electroencephalography (M/EEG) has opened the possibility to understand the relationships between brain maturation and skills development in vivo. In this review, we describe how these techniques have been applied to study the white matter maturation. At the structural level, the early architecture and myelination of bundles have been assessed with diffusion and relaxometry MRI, recently integrated in multi-compartment models and multi-parametric approaches. Nevertheless, technical limitations prevent us to map major developmental mechanisms such as fibers growth and pruning, and the progressive maturation at the bundle scale in case of mixing trajectories. At the functional level, M/EEG have been used to record different visual, somatosensory and auditory evoked responses. Because the conduction velocity of neural impulses increases with the myelination of connections, major changes in the components latency are observed throughout development. But so far, only a few studies have related structural and functional markers of white matter myelination. Such multi-modal approaches will be a major challenge in future research, not only to understand normal development, but also to characterize early mechanisms of pathologies and the influence of fetal and perinatal interventions on later outcome.
摘要：
已经在妊娠的最后三个月，功能反应记录在胎儿和早产新生儿中，证明已经很复杂的大脑结构.然后在整个童年，解剖连接进一步细化，但在不同的速率和异步周期跨功能网络。同时,婴儿逐渐获得新的精神运动和认知技能。只有最近使用非侵入性技术，例如磁共振成像（MRI）以及磁图和脑电图（M/EEG），才有可能了解体内大脑成熟与技能发展之间的关系。在这次审查中,我们描述了如何将这些技术应用于白质成熟的研究。在结构层面，束的早期结构和髓鞘形成已通过扩散和弛豫MRI评估，最近集成在多室模型和多参数方法中。然而，技术限制阻止我们绘制主要的发育机制，如纤维生长和修剪，以及在混合轨迹的情况下在束尺度上的逐渐成熟。在功能层面,M/EEG已用于记录不同的视觉，体感和听觉诱发反应。因为神经冲动的传导速度随着连接的髓鞘形成而增加，在整个开发过程中观察到组件延迟的主要变化。但到目前为止,只有少数研究有白质髓鞘形成的相关结构和功能标记。这种多模态方法将是未来研究的主要挑战，不仅要了解正常的发展，还要描述病理的早期机制以及胎儿和围产期干预对后期结局的影响。
