Besides radial glial cells, another type of neuronal progenitor cell—the basal or intermediate progenitor cells—emerges at the onset of peak neurogenesis.

They accumulate in the subventricular zone, a second proliferative region that lies above the ventricular zone. These intermediate progenitor cellss are produced by radial glial cells in the ventricular zone through asymmetric cell division and migrate radially to the subventricular zone, where they divide symmetrically to generate two postmitotic neurons. Intermediate progenitor cells can also divide symmetrically to produce a pair of progenitors and each could subsequently generate a pair of neurons.