Department of Electronics, Information and Bioengineering, Politecnico di Milano, Milan, Italy.
Department of Neurosciences and Mental Health, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
Sci Rep. 2023 Mar 9;13(1):3921. doi: 10.1038/s41598-023-30672-2.
The brain's intrinsic organization into large-scale functional networks, the resting state networks (RSN), shows complex inter-individual variability, consolidated during development. Nevertheless, the role of gene and environment on developmental brain functional connectivity (FC) remains largely unknown. Twin design represents an optimal platform to shed light on these effects acting on RSN characteristics. In this study, we applied statistical twin methods to resting-state functional magnetic resonance imaging (rs-fMRI) scans from 50 young twin pairs (aged 10-30 years) to preliminarily explore developmental determinants of brain FC. Multi-scale FC features were extracted and tested for applicability of classical ACE and ADE twin designs. Epistatic genetic effects were also assessed. In our sample, genetic and environmental effects on the brain functional connections largely varied between brain regions and FC features, showing good consistency at multiple spatial scales. Although we found selective contributions of common environment on temporo-occipital connections and of genetics on frontotemporal connections, the unique environment showed a predominant effect on FC link- and node-level features. Despite the lack of accurate genetic modeling, our preliminary results showed complex relationships between genes, environment, and functional brain connections during development. A predominant role of the unique environment on multi-scale RSN characteristics was suggested, which needs replications on independent samples. Future investigations should especially focus on nonadditive genetic effects, which remain largely unexplored.
大脑的固有组织形成大规模的功能网络，即静息状态网络（RSN），表现出复杂的个体间可变性，在发育过程中得到巩固。然而，基因和环境对发育中大脑功能连接（FC）的影响在很大程度上仍然未知。双胞胎设计代表了一个探索这些作用于 RSN 特征的影响的最佳平台。在这项研究中，我们应用统计双胞胎方法对 50 对年轻双胞胎（年龄在 10-30 岁之间）的静息状态功能磁共振成像（rs-fMRI）扫描进行分析，初步探讨了大脑 FC 的发育决定因素。提取了多尺度 FC 特征，并测试了经典 ACE 和 ADE 双胞胎设计的适用性。还评估了上位遗传效应。在我们的样本中，遗传和环境对大脑功能连接的影响在大脑区域和 FC 特征之间差异很大，在多个空间尺度上具有很好的一致性。尽管我们发现共同环境对颞枕连接有选择性贡献，遗传对额颞连接有贡献，但独特环境对 FC 链路和节点水平特征的影响更为显著。尽管缺乏准确的遗传建模，但我们的初步结果显示了基因、环境和发育过程中功能大脑连接之间的复杂关系。建议独特环境对多尺度 RSN 特征起主要作用，需要在独立样本中进行复制。未来的研究应特别关注遗传的非加性效应，这方面的研究还很少。
