EFFECT OF THE MONO-SIALOGANGLIOSIDE AND TETRA-SIALOGANGLIOSIDE, GM1 AND GQ1B, ON LONG-TERM POTENTIATION IN THE CA1 HIPPOCAMPAL-NEURONS OF THE GUINEA-PIG
H. Furuse et al., EFFECT OF THE MONO-SIALOGANGLIOSIDE AND TETRA-SIALOGANGLIOSIDE, GM1 AND GQ1B, ON LONG-TERM POTENTIATION IN THE CA1 HIPPOCAMPAL-NEURONS OF THE GUINEA-PIG, Experimental Brain Research, 123(3), 1998, pp. 307-314
Effects of the mono- and tetra-sialogangliosides, GM1 and GQ1b, on lon
g-term potentiation (LTP) were investigated in the CA1 neurons of guin
ea-pig hippocampal slices. The magnitude of LTP induced by a strong te
tanus (100 Hz, 100 pulses) was not significantly affected by applicati
on of either ganglioside. In contrast, when LTP was induced by a weak
tetanus (100 Hz, 4 pulses), a significantly greater LTP was induced in
the presence of either ganglioside. Similarly, when slices were incub
ated in low-Ca2+ (1.0-1.1 mM) medium for more than 2 h, the LTP was us
ually small or absent, but showed a significant increase in amplitude
of population spike (A-PS) when the slices were incubated with either
GM1 or GQ1b (4-5 mu g/ml). In addition, the application of GQ1b (4 mu
g/ml) reversed the blocking effect of an NMDA-receptor antagonist, APP
-5 (10 mu M), on the induction of LTP and resulted in forming LTP. Bas
ed on these findings, we conclude that GM1 and GQ1b exert positive mod
ulatory effects on the induction of LTP in hippocampal CA1 neurons and
suggest that GM1 and GQ1b may participate in the induction of LTP as
donors of Ca2+ ions.