Institute of Neuroscience and Medicine, Brain and Behaviour (INM-7), Research Center Jülich, Wilhelm-Johnen-Straße, 52428, Jülich, Germany.
Otto Hahn Cognitive Neurogenetics Group, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1A, 04103, Leipzig, Germany.
Commun Biol. 2023 Nov 22;6(1):1188. doi: 10.1038/s42003-023-05553-z.
The reciprocal connections between the cerebellum and the cerebrum have been suggested to simultaneously play a role in brain size increase and to support a broad array of brain functions in primates. The cerebello-cerebral system has undergone marked functionally relevant reorganization. In particular, the lateral cerebellar lobules crura I-II (the ansiform) have been suggested to be expanded in hominoids. Here, we manually segmented 63 cerebella (34 primate species; 9 infraorders) and 30 ansiforms (13 species; 8 infraorders) to understand how their volumes have evolved over the primate lineage. Together, our analyses support proportional cerebellar-cerebral scaling, whereas ansiforms have expanded faster than the cerebellum and cerebrum. We did not find different scaling between strepsirrhines and haplorhines, nor between apes and non-apes. In sum, our study shows primate-general structural reorganization of the ansiform, relative to the cerebello-cerebral system, which is relevant for specialized brain functions in an evolutionary context.
小脑与大脑之间的相互联系被认为同时在大脑大小的增加和灵长类动物的广泛大脑功能中发挥作用。小脑-大脑系统经历了显著的功能相关重组。特别是，小脑外侧叶蚓部 I-II（ansiform）在人科动物中被认为是扩张的。在这里，我们手动分割了 63 个小脑（34 个灵长类物种；9 个亚目）和 30 个 ansiforms（13 个物种；8 个亚目），以了解它们的体积在灵长类谱系中是如何进化的。总的来说，我们的分析支持小脑-大脑的比例缩放，而 ansiforms 的扩张速度快于小脑和大脑。我们没有发现树鼩和原猴之间以及猿和非猿之间有不同的缩放比例。总之，我们的研究表明，ansiform 在结构上相对于小脑-大脑系统发生了普遍的重组，这在进化背景下与专门的大脑功能有关。
