Confocal laser microscopy, in conjunction with carbocyanine dyes and calcium-sensitive fluorescent indicators, was used in slices and explant cultures of developing cerebellum to study cellular mechanisms underlying a motility of neuronal cell migration. The results indicate that a combination of voltage- and ligand-activated ion channels cooperatively regulates Ca2+ influx into the migrating cells. We suggest that molecules, present in the local cellular milieu, affect cell motility by activating specific ion channels and second messengers that influence polymerization of stiff and contractile cytoskeletal proteins. This early interaction between postmitotic neurons and surrounding cells controls the rate of their movements, sculpts their shapes, establishes their positions, and, therefore, indirectly determines their identities to prior formation of synaptic connections.