Shen Kai-Kai, Rose Stephen, Fripp Jurgen, McMahon Katie L, de Zubicaray Greig I, Martin Nicholas G, Thompson Paul M, Wright Margaret J, Salvado Olivier
CSIRO Computational Informatics, Herston, QLD 4029, Australia.
Centre for Advanced Imaging, University of Queensland, Brisbane, Australia.
Neuroimage. 2014 Oct 15;100:628-41. doi: 10.1016/j.neuroimage.2014.06.041. Epub 2014 Jun 26.
Heritability of brain anatomical connectivity has been studied with diffusion-weighted imaging (DWI) mainly by modeling each voxel's diffusion pattern as a tensor (e.g., to compute fractional anisotropy), but this method cannot accurately represent the many crossing connections present in the brain. We hypothesized that different brain networks (i.e., their component fibers) might have different heritability and we investigated brain connectivity using High Angular Resolution Diffusion Imaging (HARDI) in a cohort of twins comprising 328 subjects that included 70 pairs of monozygotic and 91 pairs of dizygotic twins. Water diffusion was modeled in each voxel with a Fiber Orientation Distribution (FOD) function to study heritability for multiple fiber orientations in each voxel. Precision was estimated in a test-retest experiment on a sub-cohort of 39 subjects. This was taken into account when computing heritability of FOD peaks using an ACE model on the monozygotic and dizygotic twins. Our results confirmed the overall heritability of the major white matter tracts but also identified differences in heritability between connectivity networks. Inter-hemispheric connections tended to be more heritable than intra-hemispheric and cortico-spinal connections. The highly heritable tracts were found to connect particular cortical regions, such as medial frontal cortices, postcentral, paracentral gyri, and the right hippocampus.
大脑解剖学连接性的遗传力主要通过扩散加权成像（DWI）进行研究，主要方法是将每个体素的扩散模式建模为张量（例如，计算分数各向异性），但这种方法无法准确表示大脑中存在的许多交叉连接。我们假设不同的脑网络（即其组成纤维）可能具有不同的遗传力，并在一个由328名受试者组成的双胞胎队列中使用高角分辨率扩散成像（HARDI）研究脑连接性，该队列包括70对同卵双胞胎和91对异卵双胞胎。在每个体素中用纤维方向分布（FOD）函数对水扩散进行建模，以研究每个体素中多个纤维方向的遗传力。在一个由39名受试者组成的子队列的重测实验中估计了精度。在使用ACE模型计算同卵双胞胎和异卵双胞胎的FOD峰遗传力时考虑了这一点。我们的结果证实了主要白质束的总体遗传力，但也确定了连接网络之间遗传力的差异。半球间连接往往比半球内和皮质-脊髓连接更具遗传性。发现高度可遗传的束连接特定的皮质区域，如内侧额叶皮质、中央后回、中央旁回和右侧海马体。
