Single-cell transcriptomics of adult macaque hippocampus reveals neural precursor cell populations

The existence of adult neurogenesis in primates is controversial. Hao et al. performed single-cell RNA sequencing with immunostaining and neurosphere cultures on adult macaques and revealed robust neurogenesis in the adult macaque hippocampus. The extent to which neurogenesis occurs in adult primates remains controversial. In this study, using an optimized single-cell RNA sequencing pipeline, we profiled 207,785 cells from the adult macaque hippocampus and identified 34 cell populations comprising all major hippocampal cell types. Analysis of their gene expression, specification trajectories and gene regulatory networks revealed the presence of all key neurogenic precursor cell populations, including a heterogeneous pool of radial glia-like cells (RGLs), intermediate progenitor cells (IPCs) and neuroblasts. We identified HMGB2 as a novel IPC marker. Comparison with mouse single-cell transcriptomic data revealed differences in neurogenic processes between species. We confirmed that neurogenesis is recapitulated in ex vivo neurosphere cultures from adult primates, further supporting the existence of neural precursor cells (NPCs) that are able to proliferate and differentiate. Our large-scale dataset provides a comprehensive adult neurogenesis atlas for primates.