Cell polarity and initiation of migration

One of the features of neurons in the developing central nervous system is that they migrate away from their birthplaces to their final destinations. Neurons are generated in the ventricular zone or the subventricular zone, migrate radially through the intermediate zone to reach the cortical plate, and finish their migration beneath the marginal zone. In this chapter, we introduce the historical debates concerning neuronal migration, the current models of morphological changes during the initial phase of radial neuronal migration. We also present the molecular mechanisms that underlie the initiation and the polarity regulation of migration in the developing cerebral cortex clarified by the analyses of human diseases and the advancement of molecular biology techniques.