"Small axonless neurons": postnatally generated neocortical interneurons with delayed functional maturation.

GABAergic interneurons of the mouse cortex are generated embryonically in the ventral telencephalon. Recent evidence, however, indicated that a subset of cortical cells expressing interneuronal markers originate in the neonatal subventricular zone. This has raised interest in the functional development and incorporation of these postnatally generated cells into cortical circuits.