Effect of Ginsenosides on Efficiency of Synaptic Transmission in Hippocampal Dentate Gyrus and Behavioral Memory in Rat
Zhang Yi Lou Ailin(Oept. of Physiology, Institute of Clinical Medical Sciences, China-Japan Friend hip Hospital)
The effect of ginsenosides on PS of granular cell layer in hippocampal dentate gyrus and the memory retention were observed. Results showed, (a) ginsenosides significantly increase the amplitude of PS (averaged increase in 101.2±33.56%) , and decrease the onset latency and peak latency of PS (averaged decrease in 16±5.31% and 14.9±5.18% respsctively). Tha phenomenon lasted for about one week after stopping ginsenosides given. In the meantime, ginsenosides markedly improved memory retention in rats, (b) APV, a special antagonist of NMDA receptor complex, blocked the effect of ginsenosides mentioned above, (c) Polymyxine B, an inhibitor of protein kinase C, distinctively inhibited the ginsenosides-enhanced amplitude of PS, and damaged memory retention in rats, but it did not change the decreasing effect of ginsenosides on the la-tency of PS. It may be one of neuromechanisms for ginsenosides to promote the memory retention in rat that ginsenosides enhance the efficiency of synaptic transmission in hippocampal dentate gyrus. The protein phosphor,ylation and NMDA receptor in granular cell layer play an important role in the molecular mechanism for ginsenosides to promote memory retention.