Atypical Formation of Fiber Pathways and Cortical Folding in the Brain

摘要 新兴的大脑通路和形态学在典型和非典型的大脑发育中是联系在一起的， 利用我们的技术，可以通过MRI对变化进行三维成像。皮层回旋的发展， 脑回和脑沟是一个复杂的过程，通常发生在产前发育期间。尽管多次 理论，导致脑回/脑沟出现的神经原性过程及其与底层纤维的关系 路径仍然未知。无脑畸形（LIS）是一种罕见的神经系统疾病，其特征是缺乏 皮质回旋，提供了一个很好的模型来研究导致发展的生物过程， 脑回和脑沟。另一方面，胼胝体发育不全（AgCC）是另一种神经系统疾病， 其特征是部分或完全缺失（发育不全）连接两者的胼胝体 大脑半球这两种发育性神经障碍是很好的研究模型 纤维的非典型形成和脑回/脑沟之间的时空联系，因为LIS具有明显的脑回 畸形，但它们与潜在纤维通路的关系仍然难以捉摸，而AgCC具有明显的 异常的纤维通路，但它们与脑回结构的关系仍然是难以捉摸的。通过我们最近的 研究中，我们观察到LIS患者和AgCC患者的旋转指数明显较小， (GI)与年龄/性别匹配的对照组相比。此外，在LIS患者中， 投射通路得以保留，但短至中等长度的皮质-皮质联合通路被破坏。 缺乏或数量很少，而与AgCC患者相比， 对照这些观察结果与纤维通路和皮层神经元之间的关系一致。 折叠/表面形态学。然而，在这些和其他发育中，纤维/脑回发育的更多细节， 疾病仍然难以捉摸。在此R 01中，构建在以前的R 03上，我们将利用我们的技术来研究详细的链接 LIS和AgCC从新生儿到年轻成人阶段的纤维通路和脑回形成。

Abstract Emerging brain pathways and morphology are linked in typical and atypical brain development, and such changes can be 3-dimensionally imaged by MRI with our technique. The development of cortical convolutions, gyri and sulci, is a complex process that typically takes place during prenatal development. Despite numerous theories, neurogenic processes that cause the appearance of gyri/sulci and its relationships to underlying fiber pathways remain unknown. Lissencephaly (LIS), a rare neurological condition characterized by the lack of cortical convolutions, offers a great model to look into the biological processes that lead to the development of gyri and sulci. On the other hand, agenesis of the corpus callosum (AgCC) is another neurological disorder that is characterized by a partial or complete absence (agenesis) of the corpus callosum which connects the two cerebral hemispheres. These two developmental neurological disorders are great models to study spatiotemporal links between atypical formation of fibers and gyri/sulci, because LIS has obvious gyral malformations but their relationships to underlying fiber pathways are still elusive, while AgCC has obvious abnormal fiber pathways but their relationships to gyral structures are still elusive. Through our recent investigations, we observed that both LIS patients and AgCC patients had significantly smaller gyrification index (GI) compared to age/sex-matched controls. In addition, in patients with LIS, spatiotemporal distribution of projection pathways was preserved but short- to medium-length cortico-cortical association pathways were absent or few in number, while patients with AgCC had significantly smaller cortical surface area compared to controls. These observations are in line with suggested relationships between fiber pathways and cortical folding/surface morphology. However, more details of fiber/gyral development in these and other developmental disorders are still elusive. In this R01, built on a previous R03, we will utilize our technique to study detailed links of fiber pathways and gyral formation in LIS and AgCC ranging from newborn to young adult stages.