Young S L, Bohenek D L, Fanselow M S
Department of Psychology, University of California, Los Angeles 90024-1563.
Behav Neurosci. 1994 Feb;108(1):19-29. doi: 10.1037//0735-7044.108.1.19.
Hippocampal lesions in rats produce both a retrograde and an anterograde amnesia of contextual fear conditioning. The present experiments examined the anterograde deficit in context conditioning. The deficit produced by electrolytic hippocampal lesions was apparent when training occurred on 7, 14, or 28 days following surgery, confirming the durability of the amnesia. The role of the hippocampus in context conditioning may be related to an NMDA (N-methyl-D-aspartate) receptor-mediated process. Both NMDA hippocampal lesions and intrahippocampal administration of an NMDA antagonist produced anterograde amnesia. Animals preexposed to the conditioning context 28 days prior to hippocampal lesioning were protected from the deficit normally produced by the lesions. Thus, the hippocampus must form a contextual representation during preexposure that is subsequently stored elsewhere. Once formed this representation of the context can be associated with an unconditional stimulus.
大鼠海马体损伤会导致情境恐惧条件反射出现逆行性和顺行性失忆。本实验研究了情境条件反射中的顺行性缺陷。当在手术后7天、14天或28天进行训练时，电解海马体损伤所产生的缺陷很明显，这证实了失忆的持续性。海马体在情境条件反射中的作用可能与NMDA（N-甲基-D-天冬氨酸）受体介导的过程有关。NMDA海马体损伤和海马体内注射NMDA拮抗剂都会产生顺行性失忆。在海马体损伤前28天预先接触条件反射情境的动物，可免受损伤通常所产生的缺陷影响。因此，海马体必须在预先接触期间形成一种情境表征，随后存储在其他地方。一旦形成，这种情境表征就可以与无条件刺激相关联。
