Exogenously applied gangliosides (GM1, GD1a and Gmix) fail to facilitate the induction of long-term potentiation (LTP) in the slices of hippocampus and superior colliculus of the guinea pig.

To confirm the effect of gangliosides on the facilitation of the induction of long-term potentiation (LTP), slices of hippocampus and superior colliculus from guinea pig were prepared. One group of slices was incubated in the standard medium containing gangliosides (GM1, GD1a, or a mixture of gangliosides from bovine brain, each at a concentration of 70 microM) for 2 h. The other group of slices was incubated in the standard medium only. In both groups of slices, tetanic stimulation induced LTP in a similar manner. In low Ca2+ (1 mM) medium, LTP was not induced in either group of slices. Thus, the present experiments could not confirm previous reports indicating that exogenously applied gangliosides facilitate the induction of LTP.