Effects of gangliosides on the in vitro development of neuroblastoma cells: An ultrastructural study

The role of gangliosides in neuronal differentiation was studied by adding a mixture of bovine brain gangliosides to mouse neuroblastoma cells which were induced to differentiate through the application of γ-aminobutyric acid (GABA) or sodium bromide (NaBr). GABA or NaBr was applied to 5-day-old cultures at concentrations ranging from 10(-4) to 10(-5)M. The cells were exposed to these substances over short periods of time (2 days). A mixture of bovine brain gangliosides was added to the 7-day-old cultures for 24-28 h. Electron microscopy revealed that ganglioside-induced morphological differentiation was accompanied by a significant number of mature synapse-like contacts. The GM1 gangliosides fraction apparently plays an important role in the formation of mature synapses, since none were observed when the GM1 was removed from the ganglioside mixture.