Reyes Laura D, Do Kim Young, Issa Habon, Hopkins William D, Mackey Scott, Sherwood Chet C
Center for the Advanced Study of Human Paleobiology, The George Washington University, 800 22nd St. NW, Suite 6000, Washington, DC, 20052, USA.
Sackler Institute of Graduate Biomedical Sciences, New York University, New York, NY, 10016, USA.
Brain Struct Funct. 2023 Jan;228(1):63-82. doi: 10.1007/s00429-022-02514-w. Epub 2022 Jun 8.
The parietal lobe is a region of especially pronounced change in human brain evolution. Based on comparative neuroanatomical studies, the inferior parietal lobe (IPL) has been shown to be disproportionately larger in humans relative to chimpanzees and macaques. However, it remains unclear whether the underlying histological architecture of IPL cortical areas displays human-specific organization. Chimpanzees are among the closest living relatives of humans, making them an ideal comparative species to investigate potential evolutionary changes in the IPL. We parcellated the chimpanzee IPL using cytoarchitecture and myeloarchitecture, in combination with quantitative comparison of cellular features between the identified cortical areas. Four major areas on the lateral convexity of the chimpanzee IPL (PF, PFG, PG, OPT) and two opercular areas (PFOP, PGOP) were identified, similar to what has been observed in macaques. Analysis of the quantitative profiles of cytoarchitecture showed that cell profile density was significantly different in a combination of layers III, IV, and V between bordering cortical areas, and that the density profiles of these six areas supports their classification as distinct. The similarity to macaque IPL cytoarchitecture suggests that chimpanzees share homologous IPL areas. In comparison, human rostral IPL is reported to differ in its anatomical organization and to contain additional subdivisions, such as areas PFt and PFm. These changes in human brain evolution might have been important as tool making capacities became more complex.
顶叶是人类大脑进化过程中变化尤为显著的一个区域。基于比较神经解剖学研究，相对于黑猩猩和猕猴，人类的顶下小叶（IPL）已被证明不成比例地更大。然而，IPL皮质区域潜在的组织学结构是否呈现出人类特有的组织形式仍不清楚。黑猩猩是人类现存的近亲之一，这使它们成为研究IPL潜在进化变化的理想比较物种。我们利用细胞结构和髓鞘结构对黑猩猩的IPL进行了划分，并对所确定的皮质区域之间的细胞特征进行了定量比较。在黑猩猩IPL的外侧凸面上确定了四个主要区域（PF、PFG、PG、OPT）和两个岛盖区域（PFOP、PGOP），这与在猕猴中观察到的情况相似。细胞结构定量分析表明，相邻皮质区域之间的III、IV和V层组合中的细胞轮廓密度存在显著差异，并且这六个区域的密度轮廓支持将它们分类为不同的区域。与猕猴IPL细胞结构的相似性表明黑猩猩具有同源的IPL区域。相比之下，据报道人类IPL的嘴侧部分在解剖组织上有所不同，并且包含额外的细分区域，如PFt和PFm区域。随着工具制造能力变得更加复杂，人类大脑进化中的这些变化可能很重要。
