Atypical Formation of Fiber Pathways and Cortical Folding in the Brain

摘要 新出现的大脑通路和形态在典型和非典型大脑发育中是相关的，这样 使用我们的技术，MRI可以对变化进行三维成像。大脑皮质卷曲的发展， 脑回和脑沟是一个复杂的过程，通常发生在产前发育期间。尽管有许多 导致脑回/脑沟出现的理论、神经发生过程及其与潜在纤维的关系 目前尚不清楚具体的途径。无脑畸形(LIS)，一种罕见的神经系统疾病，其特征是缺乏 皮质卷曲，提供了一个很好的模型来研究导致脑血管疾病发展的生物过程。 脑回和脑沟。另一方面，痴呆体发育不全(Agcc)是另一种神经系统疾病， 其特征是部分或完全缺乏(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。 纤维的不典型形成与脑回/脑沟之间的时空联系，因为LIS有明显的脑回 畸形，但它们与潜在的纤维通路的关系仍然难以捉摸，而AGCC有明显的 异常的纤维通路，但它们与脑回结构的关系仍然难以捉摸。通过我们最近的 调查中，我们观察到LIS患者和AGCC患者的旋转指数都明显较小 (GI)与年龄/性别匹配的对照组进行比较。此外，在LIS患者中，LIS的时空分布 保留了投射通路，但保留了中短长度的皮质-皮质联合通路 缺乏或数量很少，而AGCC患者的皮质表面积与 控制。这些观察结果与纤维通路和皮质之间的关系是一致的。 折叠/表面形态。然而，这些和其他发育中的纤维/脑回发育的更多细节 疾病仍然难以捉摸。在本R01中，我们将在以前的R03的基础上，利用我们的技术研究详细的链接 LIS和AGCC从新生儿到青壮年的纤维通路和脑回形成的研究。

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.