contributes to morphology of olfactory bulb olfactory bulb layer olfactory bulb subependymal zone The region of mitotically active layer of cells surrounding the lateral brain ventricles that consists of migrating neuroblasts, astrocytes and transitory amplifying progenitor cells, that produce neurons that migrate to the olfactory bulb. MA:0000974 UBERON:0005380 EMAPA:35612