PRESYNAPTIC ENHANCEMENT SHOWN BY WHOLE-CELL RECORDINGS OF LONG-TERM POTENTIATION IN HIPPOCAMPAL SLICES
PRESYNAPTIC ENHANCEMENT SHOWN BY WHOLE-CELL RECORDINGS OF LONG-TERM POTENTIATION IN HIPPOCAMPAL SLICES
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DOI：
10.1038/346177a0
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发表时间：
1990-07-12
期刊：
影响因子：
64.8
通讯作者：
TSIEN, RW
中科院分区：
文献类型：
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作者：
MALINOW, R;TSIEN, RW
海马中突触传递的长时程增强（LTP）是用于理解记忆的细胞机制的广泛研究的模型系统1 -6。在CA 1区，LTP在突触后7 - 10由Ca 2+依赖性11，12蛋白激酶激活触发13，14，但持续修饰的位点仍有争议15 -25。突触变异性的统计分析已被提出作为解决这一争论的一种手段3，26，虽然一个主要的障碍是传统的细胞内记录的信噪比差。我们应用全细胞电压钳技术27研究了传统海马脑片的突触传递（比较参考文献28-30）。在这里，我们报告说，强大的LTP可以记录有很大的改善信号分辨率和生化访问突触后细胞。突触后细胞的长时间透析阻断了LTP的触发，而对LTP的表达没有影响。改进的信号分辨率揭示了试验间的较大变异性，反映了发射器释放的概率性质31 -35。突触变异性的变化以及LTP期间突触失败比例的降低表明递质释放显着增强。
LONG-TERM potentiation (LTP) of synaptic transmission in the hippocampus is a widely studied model system for understanding the cellular mechanisms of memory1–6. In region CA1, LTP is triggered postsynaptically7–10by Ca2+-dependent11,12activation of protein kinases13,14, but the locus of persistent modification remains controversial15–25. Statistical analysis of synaptic variability has been proposed as a means of settling this debate3,26, although a major obstacle has been the poor signal-to-noise ratio of conventional intracellular recordings. We have applied the whole-cell voltage clamp technique27to study synaptic transmission in conventional hippocampal slices (compare refs 28–30). Here we report that robust LTP can be recorded with much improved signal resolution and biochemical access to the postsynaptic cell. Prolonged dialysis of the postsynaptic cell blocks the triggering of LTP, with no effect on expression of LTP. The improved signal resolution unmasks a large trial-to-trial variability, reflecting the probabilistic nature of transmitter release31–35. Changes in the synaptic variability, and a decrease in the proportion of synaptic failures during LTP, suggest that transmitter release is significantly enhanced.