EXOGENOUS GANGLIOSIDES MODULATE CALCIUM FLUXES IN CULTURED NEURONAL CELLS

Previous work from this and other laboratories has shown that the neuritogenic effect due to exogenous gangliosides on primary neurons in culture is accompanied by several morphological and biochemical modifications. The present results indicate that the treatment of these neurons with gangliosides, under the experimental conditions which are known to produce a sprouting effect, inhibited the influx of Ca-45(2+) and increased the release of Ca-45(2+) from the cells. No significant differences were noted using concentrations of gangliosides (10(-8)-10(-5) M) either below or above the critical micellar concentrations. No apparent specificity was observed among various species of individual sialocompounds (GM1, GD1a). Moreover the presence or absence of fetal calf serum in the culture medium influenced the levels of Ca-45(2+) fluxes. This study confirms the hypothesis that gangliosides may be considered as Ca2+ flux modulators in neuronal cells.