Barrientos Ruth M, O'Reilly Randall C, Rudy Jerry W
Department of Psychology and The Center for Neuroscience, University of Colorado, CB345, Boulder, CO 80309, USA.
Behav Brain Res. 2002 Aug 21;134(1-2):299-306. doi: 10.1016/s0166-4328(02)00045-1.
Pre-exposure to the context facilitates the small amount of contextual fear conditioning that is normally produced by immediate shock. This context pre-exposure facilitation effect provides a convenient way to study the rat's learning about context. We recently reported that anterograde damage to dorsal hippocampus prevents this facilitation. The present experiments strengthen this conclusion by showing that the protein synthesis inhibitor, anisomycin, injected bilaterally into the dorsal hippocampus following context pre-exposure also significantly reduces the facilitation effect. The same treatment given immediately after immediate shock, however, had no effect on facilitation. These results support theories that assume that, (a) contextual fear involves two processes, acquiring and storing a conjunctive representation of a context and associating that representation with fear; and (b) the hippocampus contributes to contextual fear by participating in the storage of the memory representation of the context.
对环境的预暴露促进了通常由即时电击产生的少量情境恐惧条件反射。这种环境预暴露促进效应为研究大鼠对环境的学习提供了一种便捷的方法。我们最近报道,背侧海马的顺行性损伤会阻止这种促进作用。本实验通过表明在环境预暴露后双侧注射到背侧海马的蛋白质合成抑制剂茴香霉素也显著降低促进效应,强化了这一结论。然而,在即时电击后立即给予相同处理对促进作用没有影响。这些结果支持了以下理论:(a)情境恐惧涉及两个过程,获取并存储环境的联合表征,并将该表征与恐惧联系起来;(b)海马通过参与环境记忆表征的存储来促进情境恐惧。