胎脑皮质及主要纤维束的时空特异性发育

Human fetal brain development is an immensely complicated but ordered process. The description of spatio-temporal pattern of development of fetal brain cortex regions and major white matter tracts provides a chance to deeply understand the developmental relationship between brain morpholgy and function, also benefits to reveal mechanism and treatment of development-related mental disorders. Diffusion tensor imaging, as the unique non-invasive method, is useful to delineate microstructural development inside cortex and white matter. In our previous study, gene expression analysis with some neuroanatomical criteria was used to identify function-related 12 region-of-intereseting on fetal brain cortical surface, making the probability to reveal the developmental relationship between microstructural changes and brain function. In this study, 240 fetus and neonates with age rang from 20 to 40 gestational weeks will be recruited and high-resolution, high-SNR DTI data will be collected. Analyzing data through distracting diffusion indices from defined cortical region-of-intereseting and tracked tracts, we are trying to illustrate (i) developmental trajectories of spatio-temporal pattern of fetal brain cortical regions and tracts; (ii) the relationship between macrostructural changes in cortial regions and white matter tracts during development; (iii) dynamic spatio-temporal atlas will be established which includes the age-specific atlas of each gestational week.

胎脑发育是一个复杂而有序的过程。描述胎脑皮质区域及纤维束独特的时间空间特异性发育模式，有助于深入理解大脑形态与功能发育的关系，并为阐明发育性脑病的发病机制及治疗提供可靠的形态学基础。磁共振弥散张量成像（MR-DTI），作为目前唯一的无创性检查手段，能够定量探测发育过程中胎脑皮质及纤维束微结构的改变。我们前期工作中利用多个基因表达在胎脑皮质不同区域的差异定义了大脑功能脑区，使其成为连接大脑形态与功能的纽带，为研究胎脑微结构改变与功能发育的关系成为可能。本课题获取大样本量20-40孕周胎儿/新生儿大脑的高分辨率、高信噪比DTI数据，结合基因表达信息定义脑区并追踪纤维束，尝试揭示：（1）胎脑皮质脑功能相关区及主要纤维束的时空特异性发育曲线；（2）胎脑皮质脑功能相关脑区与主要纤维束微结构变化的发育关系；（3）构建动态的时间空间脑模板，即覆盖每一个孕周的年龄特异性模板。