丙泊酚对大鼠海马CA1区突触传递长时程抑制的作用

目的研究丙泊酚对大鼠海马CA1区兴奋性突触反应及突触可塑性的影响。方法取3周龄Wistar大鼠,快速断头取脑,用振动切片机切取400μm厚的海马脑片,电刺激靠近海马CA1区的Schaffer纤维,用全细胞膜片钳技术记录CA1区锥体细胞的兴奋性突触后电流(excitatory post-synaptic current,EPSC)。循环液中加入不同浓度的丙泊酚,观察其对EPSC的影响。然后给与低频刺激(900pulse,3Hz)诱导长时程抑制(long-termdepression,LTD),并观察丙泊酚对LTD诱导的影响。结果丙泊酚呈剂量依赖性地抑制EPSC,其作用可被印防己毒素(picrotoxin)阻断;丙泊酚可易化由N-甲基-D-门冬氨酸(N-methyl-D-aspartate,NMDA)受体介导的LTD的诱导。结论丙泊酚可影响大鼠海马CA1区的兴奋性突触传递和突触可塑性,从而对大鼠的学习和记忆产生影响。

Efficacy of propofol on long-term depression in the CA1 region of rat hippocampus

Objective To evaluate the impact of propofol on excitatory synaptic responses and synaptic plasticity in rat hippocampus.Methods Male Wistar rats(3 week old)were decapitated rapidly and the hippocampal brain slices were cut coronally in 400 μm.The microscope was used to identify the CA1 region of the hippocampus.With electrical stimulation on Schaffer collaterals,the excitatory post-synaptic current(EPSC)were recorded using blind patch-clamp technique;after 10min recording of EPSC baseline,propofol was perfused in bath solution with different concentrations.Then EPSC was continously recorded for another 30min.The impact of propofol on synaptic plastisity after 10min recording of EPSC baseline was observed after low frequency stimulation(LFS,0.3Hz,900pulse)was used to induce LTD.Then the slice was incubated with propofol for 0.5h and LTD was induced as above.Results Propofol dose-dependently inhibited EPSC,this effect can be completely blocked by picrotoxin.Propofol also facilitated LTD induction,which was depended on NMDA receptors.Conclusion Propofol can affect excitatory synaptic transmission and synaptic plasticity in the CA1 area of the rat hippocampus,so it can affect learning and memory in rats.