Ramos J M
Departamento de Psicología Experimental y Fisiología del Comportamiento, Facultad de Psicología, Instituto de Neurociencias, F. Oloriz, Universidad de Granada, Spain.
Eur J Neurosci. 1998 Oct;10(10):3295-301. doi: 10.1046/j.1460-9568.1998.00388.x.
Several recent studies have shown a flat retrograde amnesia for spatial information following lesions to the hippocampus in rats and mice. However, the results of the present investigation demonstrate that in rats that presurgically learned a spatial reference memory task based on extramaze cues, a temporally graded retrograde amnesia is evident following lesions to the hippocampus (1, 16, 32 or 64 days after learning) if two conditions are met. First, that a wide range of retention intervals is used, and second, that independent groups of rats are tested, not a single group that learns different spatial discrimination tasks at different times (expt 1). The results of expt 2 show that the hippocampus does not serve as a consolidating mechanism when the spatial task learned presurgically is based on intramaze cues. Taken together, these results indicate that the hippocampus is critical for the storage and/or retrieval of spatial reference information that was learned up to 1 month before hippocampus damage; however, in the absence of the hippocampus, efficient retention can still occur provided that the spatial knowledge was learned in a simple associative manner.
最近的几项研究表明，大鼠和小鼠海马体受损后，对空间信息会出现平缓的逆行性遗忘。然而，本研究的结果表明，对于术前基于迷宫外部线索学习了空间参考记忆任务的大鼠，如果满足两个条件，那么在海马体受损后（学习后1、16、32或64天）会出现时间梯度性逆行性遗忘。首先，使用了广泛的保留间隔；其次，对独立的大鼠组进行测试，而不是对在不同时间学习不同空间辨别任务的单个组进行测试（实验1）。实验2的结果表明，当术前学习的空间任务基于迷宫内部线索时，海马体并不作为一种巩固机制。综合来看，这些结果表明，海马体对于存储和/或检索海马体损伤前长达1个月所学的空间参考信息至关重要；然而，如果空间知识是以简单的联想方式学习的，那么在没有海马体的情况下，仍然可以有效地保持记忆。
