MECHANISM OF MIGRATION OF OLFACTORY-BULB INTERNEURONS

Neuroblasts in the subventricular zone of the walls of the lateral ven tricle in the brain of young and adult rodents migrate into the olfact ory bulb where they differentiate into local interneurons. These cells move closely associated with each other, forming chains without radia l glial or axonal guidance. The migrating neuroblasts express PSA-NCAM on their surface and PSA residues are crucial for cell-cell interacti on during chain migration. This migration occurs throughout the latera l wall of the lateral ventricle, where the precursors form an extensiv e network of chains. Cells remain organized as chains until they reach the olfactory bulb, where they disperse organized as chains until the y reach the olfactory bulb, where they disperse radially as individual cells. Chain migration defines a novel form of neuronal precursor tra nslocation which is based on homotypic interactions between cells.