Corcoran Kevin A, Maren Stephen
Department of Psychology and Neuroscience Program, University of Michigan, Ann Arbor, Michigan 48109, USA.
Learn Mem. 2004 Sep-Oct;11(5):598-603. doi: 10.1101/lm.78704.
After extinction of fear to a Pavlovian conditional stimulus (CS), contextual stimuli come to regulate the expression of fear to that CS. There is growing evidence that the context dependence of memory retrieval after extinction involves the hippocampus. In the present experiment, we examine whether hippocampal involvement in memory retrieval after extinction is related to the history of CS presentations in the context used for retrieval testing. We used infusions of muscimol to inactivate the dorsal hippocampus (DH) during postextinction retrieval tests that were conducted in contexts that differed in their history of CS presentations in that context. We found that DH inactivation affected the context-dependent retrieval of extinction (i.e., renewal) when testing occurred in a context that had no history of CS exposure, but not in a context that reliably predicted the CS. These results are discussed in terms of theories regarding the role of the hippocampus in contextual memory retrieval.
在对巴甫洛夫条件刺激（CS）的恐惧消退后，情境刺激开始调节对该CS的恐惧表达。越来越多的证据表明，消退后记忆提取的情境依赖性涉及海马体。在本实验中，我们研究了海马体在消退后记忆提取中的参与是否与用于提取测试的情境中CS呈现的历史有关。我们在消退后提取测试期间使用注入蝇蕈醇来使背侧海马体（DH）失活，这些测试是在其CS呈现历史不同的情境中进行的。我们发现，当在没有CS暴露历史的情境中进行测试时，DH失活会影响消退的情境依赖性提取（即恢复），但在可靠预测CS的情境中则不会。我们根据关于海马体在情境记忆提取中的作用的理论来讨论这些结果。
