Figure 2.
Multistep mode of neuronal migration. Postmitotic excitatory neurons are generated at the ventricular zone (VZ) or subventricular zone (SVZ) (See the enlarged drawing of the VZ and SVZ in Fig. 1) and migrate radially toward the pial surface (Blue cells). Neurons first display multipolar morphology at the lower part of the intermediate zone (IZ) and transform into locomoting neurons. Locomoting neurons possess a leading process and migrate over a long distance along radial glial fibers with elongation of an axon in a reverse direction. The migration mode switches from the locomotion mode into a radial glial fiber-independent terminal translocation mode during the final phase of migration. CP, cortical plate; IZ, intermediate zone; MZ, marginal zone; SVZ, subventricular zone; and VZ, ventricular zone.