Queensland Brain Institute, University of Queensland, Brisbane QLD, Australia.
Imaging Genetics Center, University of Southern California, Marina del Rey, CA, USA.
Cereb Cortex. 2019 Mar 1;29(3):952-962. doi: 10.1093/cercor/bhy002.
Quantifying the genetic architecture of the cerebral cortex is necessary for understanding disease and changes to the brain across the lifespan. Prior work shows that both surface area (SA) and cortical thickness (CT) are heritable. However, we do not yet understand the extent to which region-specific genetic factors (i.e., independent of global effects) play a dominant role in the regional patterning or inter-regional associations across the cortex. Using a population sample of young adult twins (N = 923), we show that the heritability of SA and CT varies widely across regions, generally independent of measurement error. When global effects are controlled for, we detected a complex pattern of genetically mediated clusters of inter-regional associations, which varied between hemispheres. There were generally weak associations between the SA of different regions, except within the occipital lobe, whereas CT was positively correlated within lobar divisions and negatively correlated across lobes, mostly due to genetic covariation. These findings were replicated in an independent sample of twins and siblings (N = 698) from the Human Connectome Project. The different genetic contributions to SA and CT across regions reveal the value of quantifying sources of covariation to appreciate the genetic complexity of cortical structures.
量化大脑皮层的遗传结构对于理解疾病和整个生命周期中大脑的变化是必要的。先前的研究表明，脑表面积（SA）和皮质厚度（CT）都是可遗传的。然而，我们还不知道特定区域的遗传因素（即独立于全局效应）在多大程度上对大脑皮层的区域模式或区域间关联起主导作用。利用一个年轻成年双胞胎的群体样本（N=923），我们表明，SA 和 CT 的遗传率在不同区域差异很大，通常与测量误差无关。当控制全局效应时，我们检测到了一个复杂的、由遗传介导的区域间关联簇模式，其在左右半球之间存在差异。不同区域的 SA 之间通常只有微弱的关联，除了在枕叶内，而 CT 在脑叶内部分割中呈正相关，在脑叶间呈负相关，这主要是由于遗传上的协变。这些发现在来自人类连接组计划的双胞胎和兄弟姐妹的独立样本（N=698）中得到了复制。SA 和 CT 在不同区域的不同遗传贡献揭示了量化协变来源的价值，以了解皮质结构的遗传复杂性。
