The control of neuronal identity in the developing cerebral cortex.

Recent studies of the lineages and developmental potential of cortical neurons show that cell fates are progressively restricted during cerebral cortical development. Cell lineage experiments suggest that individual cortical precursors are multipotent, as their progeny can end up in different cortical areas, and in different layers within an area. Transplantation studies have shown that young neurons are committed very early on to adopting a given laminar position, in a manner correlated with their birth date in the ventricular zone. Neurons in different neocortical areas, however, retain a functional and anatomical equipotentiality well into cortical development, suggesting that positional cues determine a cell's area-specific identity.