Furuse H, Waki H, Kaneko K, Fujii S, Miura M, Sasaki H, Ito K I, Kato H, Ando S
Department of Physiology, Yamagata University School of Medicine, Japan.
Exp Brain Res. 1998 Dec;123(3):307-14. doi: 10.1007/s002210050573.
Effects of the mono- and tetra-sialogangliosides, GM1 and GQ1b, on long-term potentiation (LTP) were investigated in the CA1 neurons of guinea-pig hippocampal slices. The magnitude of LTP induced by a strong tetanus (100 Hz, 100 pulses) was not significantly affected by application 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 incubated in low-Ca2+ (1.0-1.1 mM) medium for more than 2 h, the LTP was usually 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 microg/ml). In addition, the application of GQ1b (4 microg/ml) reversed the blocking effect of an NMDA-receptor antagonist, APP-5 (10 microM), on the induction of LTP and resulted in forming LTP. Based on these findings, we conclude that GM1 and GQ1b exert positive modulatory 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.
研究了单唾液酸神经节苷脂GM1和四唾液酸神经节苷脂GQ1b对豚鼠海马脑片CA1神经元长时程增强（LTP）的影响。强强直刺激（100Hz，100个脉冲）诱导的LTP幅度不受任何一种神经节苷脂应用的显著影响。相反，当用弱强直刺激（100Hz，4个脉冲）诱导LTP时，在存在任何一种神经节苷脂的情况下会诱导出显著更强的LTP。同样，当脑片在低钙（1.0 - 1.1mM）培养基中孵育超过2小时时，LTP通常很小或不存在，但当脑片与GM1或GQ1b（4 - 5μg/ml）一起孵育时，群体峰电位（A - PS）幅度显示出显著增加。此外，应用GQ1b（4μg/ml）可逆转NMDA受体拮抗剂APP - 5（10μM）对LTP诱导的阻断作用并导致形成LTP。基于这些发现，我们得出结论，GM1和GQ1b对海马CA1神经元LTP的诱导发挥正向调节作用，并表明GM1和GQ1b可能作为钙离子供体参与LTP的诱导。
