9-O-acetylated gangliosides (9-O-aGs) are expressed in regions of the developing brain during radial neuronal migration and an anti-9-O-aGs monoclonal antibody (JONES mAb) interferes with axonal growth. To determine the generality of 9-O-aGs expression in directional movements, we have examined their immunoreactivity with mAb JONES in the cell stream from the lateral ventricle rostral subventricular zone (LVSVZ) to the olfactory bulb (OB) in postnatal and adult rats. We show expression of 9-O-aGs both in LVSVZ, along the rostral migratory stream and in the OB in developing animals and, at lower levels, in adulthood. That suggests 9-O-aGs' involvement in tangential cell migration as well in other neural directional movements.