We generated induced excitatory neurons (iNeurons, iNs) from chimpanzee, bonobo and human stem cells by expressing the transcription factor neurogenin‑2 (NGN2). Single cell RNA sequencing (scRNAseq) showed that genes involved in dendrite and synapse development are expressed earlier during iNs maturation in the chimpanzee and bonobo than the human cells. In accordance, during the first two weeks of differentiation, chimpanzee and bonobo iNs showed repetitive action potentials and more spontaneous excitatory activity than human iNs, and extended neurites of higher total length. However, the axons of human iNs were slightly longer at 5 weeks of differentiation. The timing of the establishment of neuronal polarity did not differ between the species. Chimpanzee, bonobo and human neurites eventually reached the same level of structural complexity. Thus, human iNs develop slower than chimpanzee and bonobo iNs and this difference in timing likely depends on functions downstream of NGN2.

中文翻译：

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诱导神经元的比较揭示了人类的结构和功能成熟比猿慢

我们通过表达转录因子neurogenin-2 (NGN2) 从黑猩猩、倭黑猩猩和人类干细胞中产生诱导的兴奋性神经元（iNeurons，iNs）。单细胞 RNA 测序 (scRNAseq) 表明，参与树突和突触发育的基因在黑猩猩和倭黑猩猩的 iNs 成熟过程中比人类细胞更早表达。因此，在分化的前两周，黑猩猩和倭黑猩猩 iNs 表现出比人类 iNs 重复的动作电位和更多的自发兴奋活动，并且神经突的总长度更长。然而，人类 iN 的轴突在分化 5 周时稍长。建立神经元极性的时间在物种之间没有差异。黑猩猩、倭黑猩猩和人类神经突最终达到了相同的结构复杂程度。因此，