OLFACTORY MEMORY AND NEURONAL MIGRATION I N THE ADULT

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 inter-neurons. These cell s move closely associated with each other, forming chains without radi al glial or axonal guidance. The migrating neuroblasts express PSA-NCA M on their surface and PSA residues are crucial for cell-cell interact ion during chain migration. Cells remain organized as a chain formed b g homotypic interactions between cells until they reach the olfactory bulb, where they disperse radially as individual neurons. We propose t hat a combination of neurogenesis and neuronal replacement in the olfa ctory system provides unique advantages for olfactory learning.