AN INVESTIGATION OF DEPOTENTIATION OF LONG-TERM POTENTIATION IN THE CA1 REGION OF THE HIPPOCAMPUS
AN INVESTIGATION OF DEPOTENTIATION OF LONG-TERM POTENTIATION IN THE CA1 REGION OF THE HIPPOCAMPUS
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DOI：
10.1007/bf02738403
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发表时间：
1994-08-01
影响因子：
2
通讯作者：
COLLINGRIDGE, GL
中科院分区：
文献类型：
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作者：
BASHIR, ZI;COLLINGRIDGE, GL
我们研究了大鼠海马脑片CA 1区的长时程突触抑制。长时间的低频刺激（LFS; 900刺激在2 Hz）的谢弗侧副连合通路在幼稚切片没有诱导突触传递的长期抑制（LTD）。然而，如果长时程增强（LTP）首先在通路中被诱导，则LFS产生LTD样效应（即LTP的去增强）。在诱导LTP后2 h（研究的最长时间）可诱导去增强，并且在实验期间（随后长达40 min）保持稳定。N-甲基-D-天冬氨酸受体拮抗剂D-2-氨基-5-膦酰基戊酸酯、L-型电压门控性钙通道阻断剂尼莫地平或一氧化氮合酶抑制剂NO-硝基-L-精氨酸均不能阻断这种去增强作用。然而，去增强的幅度可逆地减少，在立体选择性的方式，由特定的代谢型谷氨酸受体（mGluR）拮抗剂（+）-α-甲基-4-羧基苯甘氨酸。这些结果表明，延长的低频刺激可导致mGluR依赖性LTP去增强。
We have investigated long-term synaptic depression in the CA1 region of rat hippocampal slices. Prolonged low-frequency stimulation (LFS; 900 stimuli delivered at 2 Hz) of the Schaffer collateral-commissural pathway in naive slices did not induce long-term depression (LTD) of synaptic transmission. However, if longterm potentiation (LTP) was firstly induced in the pathway then LFS generated an LTD-like effect (i.e. depotentiation of LTP). Depotentiation could be induced 2 h (the longest time studied) after the induction of LTP and was stable for the duration of the experiment (followed for up to 40 min). The induction of depotentiation was not blocked by the N-methyl-D-aspartate receptor antagonist D-2-amino-5-phosphonopentanoate, the L-type voltage-gated Ca2+ channel blocker nimodipine or the nitric oxide synthase inhibitor No-nitro-L-arginine. However, the magnitude of depotentiation was reversibly reduced, in a stereoselective manner, by the specific metabotropic glutamate receptor (mGluR) antagonist (+)-alpha-methyl-4-carboxyphenylglycine. These results show that prolonged low frequency stimulation can result in an mGluR-dependent depotentiation of LTP.