We separately analyzed data for each region using a two-stage procedure (Figure 1B and STAR Methods). The first stage of analysis robustly grouped cells into 8–11 broad classes (Data S2), including neurons, astrocytes, microglia/macrophages, oligodendrocytes, polydendrocytes (oligodendrocyte progenitor cells), and components of the vasculature – endothelial cells, fibroblast-like cells, and mural cells (Abbott et al., 2006; Marques et al., 2016; Vanlandewijck et al., 2018). The hippocampus, for example, yielded cells from all 11 cell classes (Figure S1B–D), including local cell classes native to the ventricle – the choroid plexus and ependymal cells - and a class undergoing adult neurogenesis (Habib et al., 2016; Hochgerner et al., 2018; Ming and Song, 2011). Distinct brain regions yielded cell classes in different proportions (Figure S1E).
