石杉碱甲对大鼠海马脑片CA1神经元θ节律及长时程增强的影响

目的:研究石杉碱甲(HupA)对大鼠海马脑片CA1锥体神经元θ节律、长时程增强的影响,以分析其增强学习记忆功能的神经细胞电生理机制。方法:应用大鼠海马脑片神经元细胞内记录技术,观察石杉碱甲对大鼠海马脑片的CA1锥体神经元θ节律、长时程增强的影响。结果:(1)未用药组出现膜电位振荡前后4～10Hz(θ节律)功率分量之和无显著性差异,但在HupA(1μmol·L-1)灌流15min后出现膜电位振荡,与用药前没有膜电位振荡的4～10Hz功率分量之和配对t检验比较有显著差异(n=3,P<0.005)。(2)在LTP期间,对照组EPSP幅度在强直刺激后30min显著性的升高(P<0.05),而HupA组在强直刺激后15min即出现显著性升高(P<0.01)。结论:HupA可增加大海马锥体神经元在θ频率范围内的功率分量,并易化LTP的诱发,这可能是其增强学习记忆功能的细胞电生理机制之一。

Effects of huperzine A on theta-rhythm and long-term potentiation in CA1 pyramidal neurons in adult rat hippocampal slices

AIM: To study the effects of huperzine A on the theta-rhythm and long-term potentiation in CA1 pyramidal neurons in adult rat hippocampal slices and to get insight into the cell electrophysiological mechanisms underlying the potentiation of learning and memory by Huperzine A. METHODS: The intracellular recordings from CA1 pyramidal neurons in hippocampal slices related to learning and memory were made to analyze the mechanisms of Hup-A action. RESULTS: Power of frequencies ranged from 4 to 10 Hz was not significantly difference between pre-membrane potential oscillations (MPOs) and post-MPOs in control group, but it was significantly (P<(0.005), n=3) changed between pre-MPOs before addition of Hup-A and post-MPOs after addition of Hup-A. During long-term potentiation (LTP), the increase of amplitudes of EPSPs was observed at post-tetanus 30 min in control group and 15 min in Hup-A group. CONCLUSION: Hup-A can increase the power of 4 to 10 Hz MPOs and facilitate induction of LTP in CA1 pyramidal neurons of rat hippocampal slices, which may contribute to the potentiation of learning and memory by Huperzine A.