Mapping Infant Brain Myelination with Magnetic Resonance Imaging
Mapping Infant Brain Myelination with Magnetic Resonance Imaging
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DOI：
10.1523/jneurosci.2106-10.2011
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发表时间：
2011-01-12
影响因子：
5.3
通讯作者：
Murphy, Declan G. M.
中科院分区：
文献类型：
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作者：
Deoni, Sean C. L.;Mercure, Evelyne;Murphy, Declan G. M.
髓鞘形成，即神经轴突周围髓鞘的形成，对正常的脑功能至关重要。髓鞘的发育使负责高级认知功能的神经系统之间的快速同步通信成为可能。尽管这一关键作用，但目前的神经成像技术，包括扩散张量和结构磁共振成像（MRI），还不可能实现体内髓鞘形成的定量可视化。尽管这些技术提供了对结构成熟的深入了解，但它们反映了发育的几个不同方面，例如轴突大小、密度、一致性和膜结构的变化；脂质、蛋白质和大分子含量；水的分区化。因此，观察到的信号变化是模糊的，阻碍了成像结果与学习、行为或认知指标之间有意义的推断。在这里，我们提出了第一个定量研究在健康的人类婴儿髓鞘形成，从3到11个月的年龄。使用一种新的髓磷脂特异性MRI技术，我们报告了一种始于小脑、脑桥和内囊的时空模式；从胼胝体的脾和视神经放射进行尾颅手术（3-4个月）；到枕叶和顶叶（4-6个月）；然后是胼胝体的膝额叶和颞叶（6-8个月）。我们的结果也提供了半球髓鞘形成率差异的初步证据。这项工作代表了我们在理解髓鞘形成的基本过程方面迈出的重要一步，并首次提供了健康人类婴儿期髓鞘成熟的体内可视化。
Myelination, the elaboration of myelin surrounding neuronal axons, is essential for normal brain function. The development of the myelin sheath enables rapid synchronized communication across the neural systems responsible for higher order cognitive functioning. Despite this critical role, quantitative visualization of myelination in vivo is not possible with current neuroimaging techniques including diffusion tensor and structural magnetic resonance imaging (MRI). Although these techniques offer insight into structural maturation, they reflect several different facets of development, e. g., changes in axonal size, density, coherence, and membrane structure; lipid, protein, and macromolecule content; and water compartmentalization. Consequently, observed signal changes are ambiguous, hindering meaningful inferences between imaging findings and metrics of learning, behavior or cognition. Here we present the first quantitative study of myelination in healthy human infants, from 3 to 11 months of age. Using a new myelin-specific MRI technique, we report a spatiotemporal pattern beginning in the cerebellum, pons, and internal capsule; proceeding caudocranially from the splenium of the corpus callosum and optic radiations (at 3-4 months); to the occipital and parietal lobes (at 4-6 months); and then to the genu of the corpus callosum and frontal and temporal lobes (at 6-8 months). Our results also offer preliminary evidence of hemispheric myelination rate differences. This work represents a significant step forward in our ability to appreciate the fundamental process of myelination, and provides the first ever in vivo visualization of myelin maturation in healthy human infancy.