The mammalian central nervous system is arguably the most complex system studied in biology. Normal function of the brain relies on the assembly of a diverse set of cell-types, including most prominently neurons, but also glial cells and vasculature. We developed and applied large-scale single-cell RNA sequencing for unbiased molecular cell-type classification in various regions of the mouse brain. First, I will describe our initial work on the cortex and hippocampus, and later give two examples where we dissect the maturation process of (I) cells from the oligodendrocyte lineage across the CNS, and (II) granule cells in the dentate gyrus. These results and our ongoing efforts demonstrate the importance of systematic molecular approaches to understanding cellular organization and dynamics in tissues.
