Scopolamine impairs acquisition and facilitates consolidation of fear conditioning: differential effects for tone vs context conditioning.
Scopolamine impairs acquisition and facilitates consolidation of fear conditioning: differential effects for tone vs context conditioning.
复制标题
东莨菪碱会损害习得并促进恐惧调节的巩固：语气调节与情境调节的不同效果。
DOI：
10.1006/nlme.1995.1018
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发表时间：
1995
影响因子：
2.7
通讯作者：
Fanselow,MS
中科院分区：
文献类型：
--
作者：
Young,SL;Bohenek,DL;Fanselow,MS
胆碱能拮抗作用影响选定的学习任务。为了了解东莨菪碱发挥其作用，学习任务差异敏感海马和杏仁核病变。海马损伤阻止了情境恐惧条件反射，而对语气条件反射没有影响。这些病变也产生了时间依赖性逆行赤字的背景条件。杏仁核对音调和语境条件反射都是必要的。为了研究胆碱能拮抗作用模拟海马损伤或杏仁核损伤的可能性，大鼠在恐惧条件反射之前或之后给予东莨菪碱（1 mg/kg）。在恐惧条件反射过程中，大鼠接受音调足电击或上下文足电击配对。通过对冻结的观察，提供了对语气和上下文的条件反射的证据。当给予训练前，东莨菪碱阻断恐惧条件的语气在剂量依赖性的方式，但没有影响的上下文条件。甲基东莨菪碱未引起张力调节受损，表明药物具有中枢作用。在恐惧条件反射后立即给予东莨菪碱的大鼠，后来在无药物状态下进行测试，比给予对照注射的大鼠对音调更加僵硬。东莨菪碱对背景冻结的影响不可靠。本研究结果提示东莨菪碱对恐惧条件反射的影响可能是通过海马和杏仁核功能受损以外的其他机制介导的。
Cholinergic antagonism impacts selected learning tasks. To understand where scopolamine exerts its action, learning tasks differentially sensitive to hippocampus and amygdala lesions were used. Hippocampal lesions prevent context fear conditioning without effect on tone conditioning. These lesions also produce a time-dependent retrograde deficit in context conditioning. The amygdala is necessary for both tone and context conditioning. To examine the possibility that cholinergic antagonism mimics hippocampal damage or amygdala damage, rats were given scopolamine (1 mg/kg) either before or after fear conditioning. In the fear conditioning procedure, rats received tone-footshock or context-footshock pairings. Evidence of conditioning to the tone and the context was provided by observation of freezing. When given prior to training, scopolamine blocked fear conditioning to the tone in a dose-dependent fashion but had no effect on context conditioning. The impairment of tone conditioning did not occur with methlyscopolamine, indicating the central action of the drug. Rats given scopolamine immediately following fear conditioning, tested later in a drug-free state, froze more to the tone than rats given a control injection. The effect of scopolamine on freezing to the context was not reliable. The present results suggest that scopolamine′s impact on fear conditioning is mediated by some mechanism other than impaired hippocampal or amygdala functioning.