Scopolamine and pavlovian fear conditioning in rats: Dose-effect analysis
Scopolamine and pavlovian fear conditioning in rats: Dose-effect analysis
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DOI：
10.1016/s0893-133x(99)00083-4
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发表时间：
1999-12-01
影响因子：
7.6
通讯作者：
Fanselow, MS
中科院分区：
文献类型：
--
作者：
Anagnostaras, SG;Maren, S;Fanselow, MS
毒蕈碱-胆碱能拮抗作用会在多种海马依赖性任务中产生学习和记忆缺陷。海马病变会产生习得缺陷和远景逆行性遗忘（对调节位置的恐惧），但不会影响对离散线索（例如音调）的远调节。为了检查该范例中毒蕈碱拮抗作用的效果，在恐惧条件训练之前或之后给予 0.01 至 100 mg/kg 的东莨菪碱（或甲基东莨菪碱），其中音调与令人厌恶的足部电击配对。通过在单独的测试中测量冻结来评估耳朵对环境和语气的感受。研究发现，训练前而不是训练后，东莨菪碱会严重损害恐惧条件反射。甲基东莨菪碱在破坏条件反射方面无效。尽管情境远调节对胆碱能破坏更敏感，但高剂量的东莨菪碱也会破坏音调调节。东莨菪碱不影响足部电击反应性，但确实产生高水平的活动。然而，多动并不直接导致调节缺陷。结论是东莨菪碱可能通过减弱海马θ节律来破坏 Cs-US 关联形成或 CS 加工。 [神经精神药理学 21:731-744, 1999] (C) 1999 美国神经精神药理学学院。由爱思唯尔科学公司出版
Muscarinic-cholinergic antagonism produces learning and memory deficits in a wide variety of hippocampal-dependent tasks. Hippocampal lesions produce both acquisition deficits and retrograde amnesia of contextual far (fear of the place of conditioning), but do not impact far conditioning to discrete cues (such as a tone). In order to examine the effects of muscarinic antagonism in this paradigm, rate were given 0.01 to 100 mg/kg of scopolamine (or methylscopolamine) either before or after a fear conditioning session in which tones were paired with aversive footshocks. Ear to the context and the tone were assessed by measuring freezing in separate tests. It was found that pretraining, but not post-training, scopolamine severely impaired fear conditioning; methylscopolamine was ineffective in disrupting conditioning. Although contextual far conditioning was more sensitive to cholinergic disruption, high doses of scopolamine also disrupted tone conditioning. Scopolamine did not affect footshock reactivity, but did produce high levels of activity However, hyperactivity was not directly responsible for deficits in conditioning. It was concluded that scopolamine disrupts Cs-US association formation or CS processing, perhaps through an attenuation of hippocampal theta rhythm. [Neuropsychopharmacology 21:731-744, 1999] (C) 1999 American College of Neuropsychopharmacology. Published by Elsevier Science Inc.