Abstract

To understand the origins of interhemispheric differences and commonalities/coupling in human brain wiring, it is crucial to determine how homologous interregional connectivities of the left and right hemispheres are genetically determined and related. To address this, in the present study, we analyzed human twin and pedigree samples with high-quality diffusion magnetic resonance imaging tractography and estimated the heritability and genetic correlation of homologous left and right white matter (WM) connections. The results showed that the heritability of WM connectivity was similar and coupled between the 2 hemispheres and that the degree of overlap in genetic factors underlying homologous WM connectivity (i.e., interhemispheric genetic correlation) varied substantially across the human brain: from complete overlap to complete nonoverlap. Particularly, the heritability was significantly stronger and the chance of interhemispheric complete overlap in genetic factors was higher in subcortical WM connections than in cortical WM connections. In addition, the heritability and interhemispheric genetic correlations were stronger for long-range connections than for short-range connections. These findings highlight the determinants of the genetics underlying WM connectivity and its interhemispheric relationships, and provide insight into genetic basis of WM connectivity asymmetries in both healthy and disease states.

中文翻译：

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遗传对人脑连通性的影响的半球间关系。

摘要

要了解人类大脑接线中半球间差异和共性/耦合的起源，确定左右半球的同源区域间连接性是如何遗传决定和相关的至关重要。为了解决这个问题，在本研究中，我们使用高质量的扩散磁共振成像成像分析了人类双胞胎和系谱样本，并估计了同源左右白质 (WM) 连接的遗传性和遗传相关性。结果表明，WM 连接的遗传力在 2 个半球之间是相似和耦合的，并且同源 WM 连接的遗传因素（即半球间遗传相关性）的重叠程度在整个人类大脑中差异很大：从完全重叠到完全非重叠. 特别是，皮质下 WM 连接的遗传力显着更强，遗传因素的半球间完全重叠的机会高于皮质 WM 连接。此外，远距离连接的遗传力和半球间遗传相关性强于短距离连接。这些发现突出了 WM 连通性及其半球间关系的遗传决定因素，并提供了对健康和疾病状态下 WM 连通性不对称的遗传基础的深入了解。远距离连接的遗传力和半球间遗传相关性强于短距离连接。这些发现突出了 WM 连通性及其半球间关系的遗传决定因素，并提供了对健康和疾病状态下 WM 连通性不对称的遗传基础的深入了解。远距离连接的遗传力和半球间遗传相关性强于短距离连接。这些发现突出了 WM 连通性及其半球间关系的遗传决定因素，并提供了对健康和疾病状态下 WM 连通性不对称的遗传基础的深入了解。