Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37235.
Département de Mathématiques, Université Paris-Saclay, ENS Paris-Saclay, CNRS, Centre Borelli, Gif-sur-Yvette, F-91190 France.
Proc Natl Acad Sci U S A. 2022 Jun 21;119(25):e2202491119. doi: 10.1073/pnas.2202491119. Epub 2022 Jun 14.
Whether the size of the prefrontal cortex (PFC) in humans is disproportionate when compared to other species is a persistent debate in evolutionary neuroscience. This question has left the study of over/under-expansion in other structures relatively unexplored. We therefore sought to address this gap by adapting anatomical areas from the digital atlases of 18 mammalian species, to create a common interspecies classification. Our approach used data-driven analysis based on phylogenetic generalized least squares to evaluate anatomical expansion covering the whole brain. Our main finding suggests a divergence in primate evolution, orienting the stereotypical mammalian cerebral proportion toward a frontal and parietal lobe expansion in catarrhini (primate parvorder comprising old world monkeys, apes, and humans). Cerebral lobe volumes slopes plotted for catarrhini species were ranked as parietal∼frontal > temporal > occipital, contrasting with the ranking of other mammalian species (occipital > temporal > frontal∼parietal). Frontal and parietal slopes were statistically different in catarrhini when compared to other species through bootstrap analysis. Within the catarrhini's frontal lobe, the prefrontal cortex was the principal driver of frontal expansion. Across all species, expansion of the frontal lobe appeared to be systematically linked to the parietal lobe. Our findings suggest that the human frontal and parietal lobes are not disproportionately enlarged when compared to other catarrhini. Nevertheless, humans remain unique in carrying the most relatively enlarged frontal and parietal lobes in an infraorder exhibiting a disproportionate expansion of these areas.
人类前额叶皮层（prefrontal cortex，PFC）的大小与其他物种相比不成比例，这是进化神经科学中一个持续存在的争论。这个问题使得对其他结构的过度/不足扩张的研究相对较少。因此，我们试图通过适应 18 种哺乳动物的数字图谱中的解剖区域来解决这个差距，从而创建一个通用的种间分类。我们的方法使用基于系统发育广义最小二乘法的数据驱动分析来评估整个大脑的解剖扩张。我们的主要发现表明，灵长类动物的进化出现了分歧，使典型的哺乳动物大脑比例朝向灵长类动物的额叶和顶叶扩张（包括旧世界猴子、猿和人类的灵长类动物亚目）。绘制的灵长类动物脑叶体积斜率排名为顶叶∼额叶＞颞叶＞枕叶，与其他哺乳动物物种的排名（枕叶＞颞叶＞额叶∼顶叶）形成对比。通过自举分析，与其他物种相比，灵长类动物的额叶和顶叶斜率在统计学上存在显著差异。在灵长类动物的额叶中，前额叶皮层是额叶扩张的主要驱动因素。在所有物种中，额叶的扩张似乎与顶叶系统相关。我们的发现表明，与其他灵长类动物相比，人类的额叶和顶叶并没有不成比例地增大。然而，在表现出这些区域不成比例扩张的亚目中，人类仍然具有最相对增大的额叶和顶叶，这使人类具有独特性。
