石杉碱甲增强大鼠海马脑片CA1锥体神经元的兴奋性突触传递

目的:观察石杉碱甲(Hup-A)对海马CA1锥体神经元兴奋性突触传递的影响,以探讨其增强学习记忆功能的神经细胞电生理机制。方法:应用大鼠海马脑片CA1锥体神经元细胞内记录技术,观察Hup-A对大鼠海马CA1锥体神经元膜电性质和刺激Schaffer侧支诱发的兴奋性突触后电位(EPSP)的影响。结果:(1)Hup-A(1μmol/L)灌流15min对CA1锥体神经元的膜电性质没有显著性影响。(2)Hup-A(0.3～3.0μmol/L)浓度依赖性使EPSP幅度升高、时程延长、曲线下面积增大,该作用可被阿托品(10μmol/L)预处理取消。(3)Hup-A对外源性谷氨酸诱导的去极化反应无明显影响。结论:Hup-A可增强CA1锥体神经元的兴奋性突触传递,其增强突触传递作用与M型乙酰胆碱受体激动有关。

Huperzine A enhances excitatory synaptic transmission in CA1 pyramidal neurons of adult rat hippocampal slices

AIM： To observe the effects of huperzine A（Hup-A） on excitatory synaptic transmission in CA1 pyramidal neurons of adult rat hippocampal slices and to gain an insight into the cellular electrophysiological mechanisms underlying the potentiation of learning and memory by Hup-A.METHODS： The intracellular recordings from CA1 pyramidal neurons in hippocampal slices related to learning and memory were made to analyze mechanisms of Hup-A actions on cell electrophysiological properties and excitatory postsynaptic potential（EPSP） evoked by stimulating Schaffer collaterals.RESULTS：（1） During bath of Hup-A（1 μmol/L）,the changes of cell electrophysiological properties were not significant（P0.05）.（2） Superfusion of Hup-A（0.3-3.0 μmol/L,15 min） increased amplitude,duration and area under curve of EPSPs,which was concentration-dependent,recoverable,but sensitive to atropine pretreatment（10 μmol/L,n=4）.（3） Hup-A did not result in remarkable changes of depolarizing response induced by exogenous glutamate（n=5）.CONCLUSION： By the facilitation of the synaptic transmissions,Hup-A may potentiate the activities of hippocampal CA1 pyramidal neurons,and its actions on EPSP is related to the excitation of muscarinic type of acetylcholinergic receptors.