Figure 2. Neocortical cell types.

In mice, single cell transcript sequencing of unselected neocortical cells followed by unbiased clustering analyses revealed a total of 47–49 cell types, which included GABAergic interneurons, glutamatergic projection neurons, oligodendrocyte progenitors, oligodendrocytes, astrocytes, microglia, vascular endothelial cells, vascular smooth muscle cells, pericytes, and ependymal cells [128,129] (illustration adapted from the Allen Brain Atlas, http://casestudies.brain-map.org/celltax). Using similar approaches, corresponding cellular subtypes were observed in the human neocortex [130], although the specific number of cell types (in humans and other species) is debated