海马MF-CA3突触习得性LTP诱导后PPF效应的变化

采用电生理学与行为学结合的方法，通过慢性微电极埋植技术及双脉冲检测技术，观察大鼠海马MF-CA3突触在明暗辨别学习过程中形成习得性长时程增强（Long-term potentiation, LTP）后双脉冲易化（Paired-pulse facilitation, PPF）效应的变化. 结果表明:Mossy fibers-CA3（MF-CA3）突触习得性LTP形成前的PPF易化率为138.36%9.25%，形成后则为114.75%8.42%，差异极显著（p 0.01），而基线对照组在长达7天的检测中，PPF易化率稳定在140%左右. 研究结果显示，MF-CA3突触的习得性LTP的表达可能与突触前递质释放的改变有关.

Change of Paired-pulse Facilitation after Behavioral LTP at MF-CA3 Synapses in Hippocampus

The technique of paired-pulse test combined with electrophysiology and behavioral learning was used to examine the effect of behavioral long-term potentiation (LTP) on paired-pulse facilitation (PPF) efficacy at hippocampal MF-CA3 synapses after behavioral learning. The results showed that in baseline (non-training) group, the PPF ratio was stable at the level of 140% or so. However, in training group, the PPF ratio was 138.36%9.25% before learning-dependent LTP and was significantly decreased to 114.75%8.42% after learning-dependent LTP induction (p 0.01). These results suggest that the expression of behavioral LTP at MF-CA3 synapses may be related to presynaptic neurotransmitter release.