Comparison of induced neurons reveals slower structural and functional maturation in humans than in apes

• Main Authors: Maria Schörnig, Xiangchun Ju, Luise Fast, Sebastian Ebert, Anne Weigert, Sabina Kanton, Theresa Schaffer, Nael Nadif Kasri, Barbara Treutlein, Benjamin Marco Peter, Wulf Hevers, Elena Taverna
• Format: Article
• Language: English
• Published: eLife Sciences Publications Ltd 2021-01-01
• Series: eLife
• Subjects: Chimpanzee; bonobo; neuronal maturation; neurodevelopment; neuronal function; evolution
• Online Access: https://elifesciences.org/articles/59323

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 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 2 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.