Department of Neurology, University of California at Los Angeles, Los Angeles, CA 90095, USA.
Neuroimage. 2011 Jan 1;54(1):25-31. doi: 10.1016/j.neuroimage.2010.08.014. Epub 2010 Aug 12.
A fundamental tenet in the field of developmental neuroscience is that brain maturation generally proceeds from posterior/inferior to anterior/superior. This pattern is thought to underlie the similar timing of cognitive development in related domains, with the dorsal frontal cortices-important for decision making and cognitive control-the last to fully mature. While this caudal to rostral wave of structural development was first qualitatively described for white matter in classical postmortem studies, and has been discussed frequently in the developmental neuroimaging literature and in the popular press, it has never been formally demonstrated continuously and quantitatively across the whole brain with magnetic resonance imaging (MRI). Here we use diffusion imaging to map developmental changes in the white matter in 32 typically-developing individuals age 5-28 years. We then employ a novel meta-statistic that is sensitive to the timing of this developmental trajectory, and use this integrated strategy to both confirm these long-postulated broad regional gradients in the timing of white matter maturation in vivo, and demonstrate a surprisingly smooth transition in the timing of white matter maturational peaks along a caudal-rostral arc in this cross-sectional sample. These results provide further support for the notion of continued plasticity in these regions well into adulthood, and may provide a new approach for the investigation of neurodevelopmental disorders that could alter the timing of this typical developmental sequence.
发展神经科学领域的一个基本原理是，大脑成熟通常是从后/下到前/上进行的。这种模式被认为是相关领域认知发展同步发生的基础，而背侧额皮质——对决策和认知控制很重要——是最后完全成熟的。虽然这种从尾部到头部的结构发育波最初是在经典的死后研究中定性描述白质的，并且在发展神经影像学文献和大众媒体中经常讨论，但从未使用磁共振成像 (MRI) 连续和定量地在整个大脑中进行正式证明。在这里，我们使用扩散成像来绘制 32 名正常发育个体（年龄在 5-28 岁之间）的白质发育变化。然后，我们采用一种新的元统计学方法，该方法对该发育轨迹的时间敏感，并使用这种综合策略来确认白质成熟时间的这些长期推测的广泛区域梯度在体内，并且在这个横截面样本中沿着尾部到头部的弧线显示出白质成熟峰值的时间令人惊讶的平滑过渡。这些结果进一步支持了这些区域在成年期仍具有持续可塑性的观点，并可能为研究可能改变这种典型发育序列时间的神经发育障碍提供新方法。
