槐定碱对大鼠短时程突触可塑性的影响

Effects of Sophoridine on Short-term Synaptic Plasticity in the Dentate Gyrus of Anesthetized Rats

目的观察槐定碱对短时程突触可塑性的影响。方法采用急性埋藏电极记录麻醉大鼠海马齿状回诱发电位的方法,观察槐定碱对MPP-DG通路联系上双脉冲刺激反应的影响,分别以群峰电位幅度和群体兴奋性突触后电位上升斜率的PPR（paired-pulse ratio）为观察指标。槐定碱以腹腔注射（i.p）形式给药,剂量为6.0mg.kg-1。双脉冲刺激实验按脉冲间隔（IPIs）20~1000ms分别给出。结果槐定碱给药后,群峰电位幅度的PPR相比给药前有明显降低,但群体兴奋性突触后电位上升斜率的PPR没有明显变化。结论 6.0mg.kg-1剂量槐定碱对麻醉大鼠MPP-DG通路的短时程突触可塑性有一定的抑制作用。

Objective To investigate the effects of sophoridine on short-term synaptic plasticity in the dentate gyrus of anesthetized rats.Methods Perforant path evoked field potentials were recorded in the dentate gyrus by acutely implanted electrodes to investigate the response to paired-pulse（pp） stimulation in the MPP-DG circuit loop.The paired-pulse ratio（PPR） was employed to evaluate the effects of the drug.Sophoridine was administrated intraperitoneally at concentration of 6.0mg·kg-1.Pairs of stimulus pulses were delivered at interpulse intervals（IPIs） from 20 to 1000 ms.Results The PPR of PS amplitude decreased significantly after the administration of sophoridine.However,no significant changes by sophoridine were found in the PPR of the pEPSP slope.Conclusion The results suggest that sophoridine has some inhibitory effects on short-term plasticity in the dentate gyrus of anesthetized rats.