Scharfman H E, Sarvey J M
Neuroscience. 1985 Jul;15(3):695-702. doi: 10.1016/0306-4522(85)90071-5.
Long-term potentiation is a long-lasting enhancement of synaptic efficacy following brief, high-frequency, repetitive stimulation of a monosynaptic input. Intracellular recordings have shown that the inhibitory postsynaptic potential changes in amplitude during long-term potentiation. Yet how this may occur is unclear. To test for a possible alteration in postsynaptic sensitivity to the recurrent inhibitory transmitter gamma-aminobutyrate, we have examined the effect of gamma-aminobutyrate, focally applied to the hippocampal CA1 cell-body layer, on the extracellular recorded action potential (population spike). We found that the degree, duration, dose-dependence and time-course of inhibition produced by gamma-aminobutyrate are unchanged during long-term potentiation. This suggests that a change in sensitivity of CA1 pyramidal cells to the transmitter gamma-aminobutyrate is not the reason for the alteration in the inhibitory postsynaptic potential during long-term potentiation.
长时程增强是在对单突触输入进行短暂、高频、重复刺激后，突触效能的长期增强。细胞内记录显示，在长时程增强过程中，抑制性突触后电位的幅度会发生变化。然而，其发生机制尚不清楚。为了测试突触后对反复抑制性递质γ-氨基丁酸的敏感性是否可能发生改变，我们研究了局部应用于海马CA1细胞体层的γ-氨基丁酸对细胞外记录的动作电位（群体峰电位）的影响。我们发现，在长时程增强过程中，γ-氨基丁酸产生的抑制程度、持续时间、剂量依赖性和时间进程均未改变。这表明，CA1锥体细胞对递质γ-氨基丁酸的敏感性变化不是长时程增强过程中抑制性突触后电位改变的原因。
