Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany.
Department of Neurobiology, University of Chicago, Chicago, IL 60637, USA; Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL 60637, USA.
Curr Biol. 2019 Jul 8;29(13):R647-R662. doi: 10.1016/j.cub.2019.05.026.
The dramatic evolutionary expansion of the neocortex, together with a proliferation of specialized cortical areas, is believed to underlie the emergence of human cognitive abilities. In a broader phylogenetic context, however, neocortex evolution in mammals, including humans, is remarkably conservative, characterized largely by size variations on a shared six-layered neuronal architecture. By contrast, the telencephalon in non-mammalian vertebrates, including reptiles, amphibians, bony and cartilaginous fishes, and cyclostomes, features a great variety of very different tissue structures. Our understanding of the evolutionary relationships of these telencephalic structures, especially those of basally branching vertebrates and invertebrate chordates, remains fragmentary and is impeded by conceptual obstacles. To make sense of highly divergent anatomies requires a hierarchical view of biological organization, one that permits the recognition of homologies at multiple levels beyond neuroanatomical structure. Here we review the origin and diversification of the telencephalon with a focus on key evolutionary innovations shaping the neocortex at multiple levels of organization.
新皮层的戏剧性进化扩张，加上专门的皮质区域的大量增殖，被认为是人类认知能力出现的基础。然而，在更广泛的系统发生背景下，哺乳动物（包括人类）的新皮层进化非常保守，主要表现为共享的六层神经元结构的大小变化。相比之下，非哺乳动物脊椎动物的端脑，包括爬行动物、两栖动物、硬骨鱼和软骨鱼以及圆口类动物，具有各种各样非常不同的组织结构。我们对这些端脑结构的进化关系的理解，特别是那些基础分支的脊椎动物和无脊椎脊索动物的理解仍然是零碎的，并受到概念障碍的阻碍。要理解高度不同的解剖结构，需要有一个生物组织的层次视图，它允许在神经解剖结构之外的多个层次上识别同源性。在这里，我们重点讨论了塑造多个组织层次的新皮层的关键进化创新，回顾了端脑的起源和多样化。
