LTP-associated EPSP/spike dissociation in the dentate gyrus: GABAergic and non-GABAergic components.
LTP-associated EPSP/spike dissociation in the dentate gyrus: GABAergic and non-GABAergic components.
复制标题
齿状回中 LTP 相关的 EPSP/尖峰解离：GABA 能和非 GABA 能成分。
DOI：
10.1016/0006-8993(91)90745-h
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发表时间：
1991
期刊：
影响因子：
2.9
通讯作者：
Steward,O
中科院分区：
文献类型：
--
作者：
Tomasulo,RA;Levy,WB;Steward,O
The induction of long-term potentiation (LTP) in the dentate gyrus (DG) leads to a change in the firing characteristics of the dentate granule cells. This phenomenon, termed EPSP/spike dissociation, is seen in field potential studies as a shift to the left of the E-S curve, in which population spike amplitude is plotted against pEPSP slope at various stimulus intensities. It has been suggested that EPSP/spike dissociation reflects a decrease in feed-forward inhibition. To test this hypothesis, we blocked GABA-A neurotransmission in a circumscribed area of the DG in urethane-anaesthetized rats by inserting a micropipette filled with 8 mM bibuculline methiodide in saline. We then recorded E-S curves from 9 such electrodes and from 8 control electrodes before and after inducing LTP in the perforant path. Bicuculline prevented the LTP-associated leftward shift of the E-S curves. Instead, the E-S curve showed a consistent shift to the right at the bicuculline sites after LTP, reflecting potentiation of the pEPSP without corresponding increases in the population spike amplitude. The results indicate that the EPSP/spike relationship is controlled largely by GABAergic input, and that potentiation of the population spike in the DG depends largely on a change in the EPSP/spike relationship.
