Cellular and molecular mechanisms controlling the migration of neocortical interneurons

The discovery, approximately 15 years ago, that cortical GABAergic interneurons originate outside the pallium has revolutionized our understanding of the development of the cerebral cortex. It is now clear that glutamatergic pyramidal cells and GABAergic interneurons follow largely distinct development programs, a notion that has challenged our views on how these neurons assemble to form precise neural circuits. In this review, I summarize our current knowledge of the mechanisms that control the migration of neocortical interneurons, a process that can be subdivided into three consecutive phases: migration to the cortex, intracortical dispersion, and layering.