I explored the roles of Rho family small GTPases in neuronal migration and cerebral cortical development. I deleted Rac1, RhoA and Cdc42 in cerebral cortical neurons using in utero electroporation, but I couldn’t find obvious abnormalities in neurons lacking Rho family small GTPases. I also deleted both Rac1 and Rac3 in the developing cerebral cortex. At birth, overall morphology of the Rac1/Rac3-deleted cerebral cortex was almost normal. However, soon after birth, cortical neurons lacking both Rac1 and Rac3 began to die by apoptosis. These results suggest that Rho family small GTPases are dispensable for neuronal migration but indispensable for the survival of neurons.
