Figure 1.
Phases of migration of neocortical projection neurons. Principal phases of migration: (1), movement from the VZ to the IZ/SVZ with bipolar or “pin-like” morphology; (2), multipolar migration; (3), bipolar locomotion along radial glia (RG); (4), terminal translocation. Multipolar migration can be subdivided into further stages: 2A, initial multipolar migration of newborn post-mitotic neurons and intermediate progenitors; 2A’, division of intermediate progenitors followed by multipolar migration; 2B, axon emergence and growth; 2C, stabilization of a dominant pia-directed leading process. The left-hand side shows the principal divisions of the cortex (VZ, ventricular zone; IZ/SVZ, intermediate/subventricular zone; CP, cortical plate; MZ, marginal zone). The right-hand side indicates the major features of the local environment through which neurons migrate. See text for details.