G_D3 ganglioside is a glycolipid characteristic of immature neuroectodermal cells

Biochemical studies have indicated that the disialoganglioside, G_D3, is a major glycolipid component of the immature vertebrate CNS, but a minor element within the mature CNS. We have investigated its cellular localization in rat CNS by immunofluorescence using a mouse monoclonal antibody that recognizes G_D3. In tissue sections of postnatal CNS, the antibody bound to cells in several areas known to contain immature neuroectodermal populations: the subventricular zone beneath the lateral ventricle, the external germinative layer of the cerebellar cortex, and the dentate gyrus of the hippocampus. G_D3-containing cells were also found in developing white matter of the forebrain and cerebellar folia. Using a double-label immunofluorescence method, we found that the G_D3-positive white matter cells did not express the astrocytic marker, glial fibrillary acidic protein. In adult rat CNS, we could not detect antibody binding to neurons or glia. Scattered G_D3-positive cells were apparent in the adult subventricular zone. Our results indicate that G_D3 ganglioside is a membrane component characteristically expressed in the rat CNS by neuroectodermal stem cells, both neuronal and glial precursors.