Fig. 6.

Schematic hypothesis for neuronal generation in the neocortex. Our model proposes that one population, the radial glial cell (RG), both generates neurons and guides neuronal migration. Newborn neurons (N) generated by radial glial precursor cells ascend along the radial fiber of the parental radial glial cell. A series of asymmetric radial glial cell divisions produces a clone of cortical pyramidal neurons. After neurogenesis, some radial glial cells transform into astrocytes (A).