The migration of cortical neuron subtypes is spatially and temporally coordinated by variety of cell intrinsic and extrinsic cues. Among cell-extrinsic cues, GABA, glutamate as well as neuromodulators such as serotonin have been shown to regulate the migration of different subtypes of neurons, including interneurons (INs) and pyramidal neurons (PNs). To further investigate the role of early activity in neuronal migration, I used an in vitro optogenetic and an in vivo chemogenetic approaches in order to manipulate early activity during development. I found that increased calcium transients in migrating cortical neurons could act as a “stop signal” that promotes differentiation. The mechanisms allowing migrating neurons to gradually increase calcium transient frequency during migration could be due to increased expression of receptors and voltage-gated ions. This would render migrating cortical neurons more responsive to cell-extrinsic network activity and trigger calcium-dependent down-stream transcriptional cascades instructing terminal differentiation.