ADENOSINE ANTAGONISTS HAVE DIFFERENTIAL-EFFECTS ON INDUCTION OF LONG-TERM POTENTIATION IN HIPPOCAMPAL SLICES
ADENOSINE ANTAGONISTS HAVE DIFFERENTIAL-EFFECTS ON INDUCTION OF LONG-TERM POTENTIATION IN HIPPOCAMPAL SLICES
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DOI：
10.1002/hipo.450050109
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发表时间：
1995-01-01
期刊：
影响因子：
3.5
通讯作者：
KRNJEVIC, K
中科院分区：
文献类型：
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作者：
FORGHANI, R;KRNJEVIC, K
通过将腺苷拮抗剂 8(对磺苯基)茶碱 (8SPT) 或 8-环戊基-3,7-二氢-1,3-二丙基-1H-嘌呤-2,6-二酮 (DPCPX) 应用到切片上，同时记录 CA1 场 EPSP 和群体峰值，研究了腺苷渗漏和强直释放如何影响长时程增强 (LTP)。在第一个系列的实验中，我们应用了弱双破伤风（100 Hz，持续 1 秒），这对于在初始对照运行中诱发 LTP 是潜意识的。在同时阻断 A(1) 和 A(2) 受体的浓度 (10-50 μM) 8SPT 存在下，相同的破伤风始终诱发群体峰值的 LTP，但不会诱发兴奋性突触后电位 (EPSP)，而仅阻断 A(1) 受体的 DPCPX (50 nM) 会促进 EPSP 和群体峰值的 LTP。这些结果与之前的证据一致，即破伤风腺苷释放一方面通过A(1)受体抑制LTP，但另一方面通过A(2)受体促进LTP。在第二组实验中，8SPT(50-100μM)并没有阻止更强的破伤风刺激对EPSP和群体峰值的LTP诱导。因此，当应用更强的破伤风时，A(2) 受体激活对于 LTP 的诱导并不是必需的。总体而言，内源性腺苷释放的主要作用是对抗 LTP 诱导。 (C) 1995 Wiley-Liss, Inc.
How adenosine leakage and tetanic release might affect long-term potentiation (LTP) was investigated by applying adenosine antagonists 8(p-sulfophenyl)theophylline (8SPT) or 8-cyclopentyl-3,7-dihydro-1,3-dipropyl-1H-purine-2,6-dione (DPCPX) to slices, while recording CA1 field EPSPs and population spikes. In the first series of experiments, we applied weak double tetani (at 100 Hz, for 1 s) that were subliminal for evoking LTP in initial control runs. in the presence of 8SPT-at concentrations (10-50 mu M) which block both A(1) and A(2) receptors-the same tetani consistently evoked LTP of population spikes but not of excitatory postsynaptic potentials (EPSPs), whereas DPCPX (50 nM), which blocks only A(1) receptors, facilitated LTP of both EPSPs and population spikes. These results are consistent with previous evidence that tetanic adenosine release on the one hand depresses LTP via A(1) receptors but on the other facilitates LTP via A(2) receptors.In a second set of experiments, 8SPT (50-100 mu M) did not prevent the induction of LTP of both EPSPs and population spikes by stronger tetanic stimulation. Therefore A(2) receptor activation is not essential for the induction of LTP when stronger tetani are applied. Overall, the main effect of endogenous adenosine release is to oppose LTP induction. (C) 1995 Wiley-Liss, Inc.