Thinking out of the dish: what to learn about cortical development using pluripotent stem cells.

The development of the cerebral cortex requires the tightly coordinated generation of dozens of neuronal subtypes that will populate specific layers and areas. Recent studies have revealed how pluripotent stem cells (PSC), whether of mouse or human origin, can differentiate into a wide range of cortical neurons in vitro, which can integrate appropriately into the brain following in vivo transplantation. These models are largely artificial but recapitulate a substantial fraction of the complex temporal and regional patterning events that occur during in vivo corticogenesis. Here, we review these findings with emphasis on the new perspectives that they have brought for understanding of cortical development, evolution, and diseases.