Figure 1.

Organization of the developing mouse neocortex. The two classes of neural precursor, radial glia and short neural precursors, both reside in the Ventricular Zone (VZ) with a process attached to the apical (luminal) surface adjacent to the developing lateral ventricle. The overt structural distinction between the 2 neural precursors is that radial glia possess a process attached to the basal (cortical) surface while short neural precursors do not. During mitosis the cell body migrates to the apical surface where it will divide to generate 2 daughter cells. In the case of radial glia, the daughter cells can be new radial glia cells, basal progenitors, or post-mitotic neurons. Basal progenitors are a transient type of progenitor that resides basal to the VZ in the Subventricular Zone (SVZ), and can also self-renew as well as generate post-mitotic neurons. Post-mitotic neurons migrate away from the VZ and/or SVZ along radial glia processes through the Intermediate Zone (IZ) to populate the developing Cortical Plate (CP) in an inside-out fashion, where the deepest cortical layers are generated first. The other apical precursor type, short neural precursors, can also self-renew or generate post-mitotic neurons, however they do not produce basal progenitors.