Retrograde amnesia for visual memories after hippocampal damage in rats
Retrograde amnesia for visual memories after hippocampal damage in rats
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DOI：
10.1101/lm.788008
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发表时间：
2008-04-01
影响因子：
2
通讯作者：
Sutherland, Robert J.
中科院分区：
文献类型：
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作者：
Epp, Jonathan;Keith, Julian R.;Sutherland, Robert J.
一般认为，简单的辨别学习不需要海马体。然而，少数研究表明，海马体损伤会损害先前学习的视觉辨别任务的保留。我们认为，虽然简单的辨别学习可能在没有海马体的情况下进行，但当海马体完整时，它在这种类型的学习中起着重要作用。为了测试海马体在简单辨别学习中的作用，我们利用两个选择图片辨别任务进行了一系列实验。我们的实验证实，海马损伤后的大鼠容易学习简单的两种选择图像辨别。然而，如果这种区分是在海马体完好的时候第一次学习的，那么随后的海马体损伤会导致对这些区分的严重逆行性遗忘。此外，当训练与损伤间隔为1 d或60 d时，简单图像辨别的逆行性失忆同样严重；遥远的画面记忆也不能幸免。同样，在海马体损伤后，近期或远程获得的图片辨别学习集的规则或图式也会丢失。简单图像辨别逆行性失忆症的严重程度与备用海马组织的体积呈负相关。因此，海马体在支持简单图片辨别的长期记忆中起着至关重要的作用。
It is generally believed that the hippocampus is not required for simple discrimination learning. However, a small number of studies have shown that hippocampus damage impairs retention of a previously learned visual discrimination task. We propose that, although simple discrimination learning may proceed in the absence of the hippocampus, it plays an important role in this type of learning when it is intact. In order to test the role of the hippocampus in simple discrimination learning, we performed a series of experiments utilizing a two-choice picture discrimination task. Our experiments confirm that rats readily learn simple two-choice picture discriminations after hippocampus damage. However, if such discriminations are first learned while the hippocampus is intact, subsequent hippocampus damage causes severe retrograde amnesia for the discriminations. Furthermore, retrograde amnesia for simple picture discriminations was equally severe when the interval between training and damage was 1 d or 60 d; remote picture memories are not spared. Similarly, the rule or schema underlying a recently or remotely acquired picture discrimination learning set was lost after hippocampus damage. The severity of retrograde amnesia for simple picture discriminations is negatively correlated with the volume of spared hippocampus tissue. Thus, the hippocampus plays an essential role in long-term memories supporting simple picture discriminations.