银杏叶提取物对慢性酒精中毒大鼠学习记忆的影响

Effects of Ginkgo biloba extract 761 on learning and memory in chronic alcoholic rats

目的探讨银杏叶提取物（EGb761）对慢性酒精中毒模型大鼠学习记忆的改善作用和机制。方法将72只sD大鼠采用随机数字表法平均分为4组：对照组、慢性酒精中毒模型组、EGb761低剂量组和高剂量组，用水迷宫实验对大鼠认知能力进行评价，用电生理学方法来检测海马CA3区长时程增强（10ng-termpotentiation，L_rP）的变化。结果（1）与对照组相比，模型组大鼠寻找平台的潜伏期明显延长，高频刺激后在CA3区诱导的场兴奋性突触后电位（fieldexcitatorypostsynapticpotential，fEPSP）的平均斜率明显下降（P〈0．05，P〈0．01）。（2）与模型组相比，EGb761低剂量组和高剂量组大鼠寻找平台的潜伏期显著缩短；EGb761低剂量组[（126．16±5．84）％]和高剂量组[（141．31±5．75）％]高频刺激后诱导的fEPSP的平均斜率均明显高于模型组[（93．31±14．21）％，P=0．034，P=0．009]。结论EGb761通过促进大鼠海马突触可塑性的恢复来改善慢性酒精中毒导致的大鼠学习记忆能力障碍。

Objective To investigate the effects of extracts of Ginkgo biloba leaves （ EGb761 ） on learn- ing, memory and the hippocampal long-term potentiation （LTP） in chronic alcoholic rats. Methods 72 SD rats were randomly divided into control group, chronic alcoholism model group, low-dose EGb761 （100 mg/kg） and high-dose EGb761 （200 mg/kg） groups on average. 55% alcohol was given （ 10 ml/kg） by garages once every day for 6 weeks to create the model of chronic alcoholism. In low-dose and high-dose EGb761 groups,EGb761 was used for gastric infusion 30 minutes before model. The control group and the model group were infused with the same volume of distilled water. MoTis water maze （MWM） was used to study the spatial learning and memory in rats. Electrophysiological methods were used to observe the changes of LTP through the comparison of field excita- tory postsynaptic potential （fEPSP） slope in hippocampal CA3 region before and after high frequency stimulation （HFS）. Results （ 1 ） The escape latency （EL） of model group （ （93.31 ± 14.21 ） s） was longer than that of the control group（ （35.28 ± 6.51 ）s）. The mean slope of fEPSP （relative to baseline） after HFS in model group was （96.91 ± 7.65 ） % ,in control group was （ 177.22 ± 10.12） % ; Compared with control group, the ability of learning and memory as well as LTP obviously descended in model group. （2） Compared with model group, EGb761 （ 100,200 mg/kg） could shorten the EL. The slope of fEPSP after HFS in either low-dose（ （ 126.16 ± 5.84 ） % ） or high-dose （141.31 ± 5.75 ）% EGb761 groups was enhanced significantly compared with the model group （96.91 ±7.65）%, P=0.034, P=0.009）. Conclusion EGb761 can significantly improve the alcohol-induced memory impairment by means of accelerating the recovery of the pathological synaptic plasticity.