Diffusion MR tractography permits investigating the 3D structure of cortical pathways as interwoven paths across the entire brain. We use high-resolution scans from diffusion spectrum imaging and high angular resolution diffusion imaging to investigate the evolution of cortical pathways within the euarchontoglire (i.e., primates, rodents) lineage. More specifically, we compare cortical fiber pathways between macaques (Macaca mulatta), marmosets (Callithrix jachus), and rodents (mice, Mus musculus). We integrate these observations with comparative analyses of Neurofilament heavy polypeptide (NEFH) expression across the cortex of mice and primates. We chose these species because their phylogenetic position serves to trace the early evolutionary history of the human brain. Our comparative analysis from diffusion MR tractography, cortical white matter scaling, and NEFH expression demonstrates that the examined primates deviate from mice in possessing increased long-range cross-cortical projections, many of which course across the anterior to posterior axis of the cortex. Our study shows that integrating gene expression data with diffusion MR data is an effective approach in identifying variation in connectivity patterns between species. The expansion of corticocortical pathways and increased anterior to posterior cortical integration can be traced back to an extension of neurogenetic schedules during development in primates.

中文翻译：

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大脑连接的进化：将扩散MR术与基因表达整合在一起，突出了灵长类动物皮层皮质投射的增加。

扩散MR牵引成像可以研究皮质通路的3D结构，将其作为贯穿整个大脑的交织通路。我们使用来自扩散谱成像和高角度分辨率扩散成像的高分辨率扫描来研究真核细胞（即灵长类动物，啮齿动物）谱系内皮质途径的演变。更具体地说，我们比较了猕猴（Macaca mulatta），mar猴（Callithrix jachus）和啮齿动物（小鼠，小家鼠）之间的皮质纤维通路。我们将这些观察结果与小鼠和灵长类动物皮层中神经丝重多肽（NEFH）表达的比较分析进行整合。我们选择这些物种是因为它们的系统发育位置可追溯人类大脑的早期进化历史。我们根据弥散MR图像进行的比较分析，皮质白质的缩放和NEFH表达表明，所检查的灵长类动物具有较大的远距离跨皮层投影，它们偏离了小鼠，其中许多跨过皮层的前轴到后轴。我们的研究表明，将基因表达数据与扩散MR数据相结合是一种有效的方法，可以识别物种之间的连通性模式。在灵长类动物发育过程中，皮层皮质通路的扩展和从前到后皮质整合的增加可以追溯到神经遗传学计划的扩展。我们的研究表明，将基因表达数据与扩散MR数据整合在一起是识别物种之间连通性模式变异的有效方法。在灵长类动物发育过程中，皮层皮质通路的扩展和从前到后皮质整合的增加可以追溯到神经遗传学计划的扩展。我们的研究表明，将基因表达数据与扩散MR数据整合在一起是识别物种之间连通性模式变异的有效方法。在灵长类动物发育过程中，皮层皮质通路的扩展和从前到后皮质整合的增加可以追溯到神经遗传学计划的扩展。