Post-training administration of corticosterone enhances consolidation of contextual fear memory and hippocampal long-term potentiation in rats
Post-training administration of corticosterone enhances consolidation of contextual fear memory and hippocampal long-term potentiation in rats
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DOI：
10.1016/j.nlm.2008.10.008
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发表时间：
2009-03-01
影响因子：
2.7
通讯作者：
Fathollahi, Yaghoub
中科院分区：
文献类型：
--
作者：
Abrari, Kataneh;Rashidy-Pour, Ali;Fathollahi, Yaghoub
本研究旨在研究皮质酮对大鼠背景恐惧记忆和海马长时程增强(LTP)巩固的影响。实验一测定了皮质酮对情境恐惧记忆巩固的剂量反应效应。在背景恐惧条件反射任务训练后，大鼠立即接受了不同剂量的皮质酮。24小时后的测试表明，皮质酮增强了倒U形的记忆巩固，这在皮质酮处理的动物的冰冻行为增加中得到了证明。最有效剂量为3 mg/kg。在实验2中，对皮质酮增强记忆巩固的大鼠进行了LTP检测。大鼠按上述方法训练，训练后即刻给予皮质酮3 mg/kg。保留试验后即刻或至多1天，用乌拉坦麻醉大鼠进行LTIP实验。对于LTIP的诱导，将3组高频刺激(每组10个刺激，频率为250 Hz)传递到穿支路径，其中S刺激30个。通过测量群体兴奋性突触后电位的初始斜率和群体峰电位的幅度来评估LTP。数据表明，被皮质酮增强记忆的动物也表现出海马LTP的增强。上述研究结果提示，糖皮质激素可能通过增强海马长时程增强而增强情景恐惧记忆的巩固。(C)2008 Elsevier Inc.保留所有权利。
This study was designed to examine the effect of corticosterone on consolidation of contextual fear memory and hippocampal long-term potentiation (LTP) in rats. In Experiment 1, dose-response effects of corticosterone on consolidation of contextual fear memory were determined. Immediately after training in contextual fear conditioning task, rats received different doses of corticosterone. Testing 24 h later, it revealed that corticosterone enhanced memory consolidation in an inverted U shape as evidenced in increased freezing behavior of corticosterone-treated animals. The most effective dose was 3 mg/kg. In Experiment 2, LTP was examined in rats whose memory consolidation has been enhanced with corticosterone. The rats were trained as the above and received corticosterone (3 mg/kg) immediately after training. Immediately or up to one day after retention test, rats were anesthetized with urethane for LTIP experiments. For LTIP induction, three episodes of high frequency stimuli, 30 s apart, were delivered to the perforant path, each consisting of 10 stimuli at 250 Hz. LTP was assessed by measuring the increase in the initial slope of the population excitatory post-synaptic potentials and the amplitude of the population spikes. Data indicated that animals whose memory has been enhanced by corticosterone, also displayed enhanced hippocampal LTP. The above findings suggest that glucocorticoids may enhance contextual fear memory consolidation via enhancing hippocampal LTP. (c) 2008 Elsevier Inc. All rights reserved.