Muller J, Corodimas K P, Fridel Z, LeDoux J E
Clinical Psychology Program, City College of the City University of New York, USA.
Behav Neurosci. 1997 Aug;111(4):683-91. doi: 10.1037//0735-7044.111.4.683.
The GABAa agonist, muscimol (0.5 microgram in 0.5 microliter saline), or vehicle was infused into the lateral and basal amygdala nuclei prior to fear conditioning or testing in rats. Rats given muscimol before conditioning and saline before testing showed much less freezing to the conditioned stimulus (CS) and the context than did controls given saline before training and testing. Rats given saline before training and muscimol prior to testing also showed low levels of freezing to the CS and the context. In follow-up procedures, rats with acquisition initially blocked by pretraining muscimol infusions froze in a manner similar to that of controls when retrained and retested with saline infusions. Rats trained with saline but tested with muscimol presumably became conditioned but could express the learning. When retested with saline, they froze in the same manner as controls. Thus, activity in the lateral and basal amygdala appears to play an essential role in the acquisition and expression of fear conditioning.
在对大鼠进行恐惧条件反射训练或测试之前，将GABAA激动剂蝇蕈醇（0.5微克溶于0.5微升生理盐水中）或溶剂注入外侧和基底杏仁核。在条件反射训练前给予蝇蕈醇且测试前给予生理盐水的大鼠，与训练和测试前均给予生理盐水的对照组相比，对条件刺激（CS）和环境的僵住反应要少得多。在训练前给予生理盐水且测试前给予蝇蕈醇的大鼠，对CS和环境的僵住反应水平也较低。在后续实验中，最初因训练前注入蝇蕈醇而阻断习得过程的大鼠，在重新用生理盐水进行训练和测试时，其僵住方式与对照组相似。用生理盐水训练但用蝇蕈醇测试的大鼠可能形成了条件反射，但无法表现出这种学习成果。当再次用生理盐水测试时，它们的僵住方式与对照组相同。因此，外侧和基底杏仁核的活动似乎在恐惧条件反射的习得和表现中起着至关重要的作用。
