Kaut K P, Bunsey M D
Department of Psychology, University of Akron, 318F Polsky Building, 225 S. Main Street, Akron, OH 44325-4301, USA.
Cogn Affect Behav Neurosci. 2001 Sep;1(3):270-86. doi: 10.3758/cabn.1.3.270.
The role of the hippocampal system in retrograde and anterograde amnesia was investigated by using a novel olfactory-guided paradigm and a traditional test of spatial learning. In the retrograde study, rats were trained on a sequence of two-choice olfactory discriminations in the weeks prior to receiving neurotoxic lesions of the hippocampus or aspiration lesions of the perirhinal-entorhinal cortex. Memory tests for preoperatively learned discriminations revealed no statistical impairment for subjects with damage to the hippocampus on a problem learned remote in time from surgery (i.e., 4 weeks +) or on the two recently learned discriminations (i.e., 1-3 weeks prior to surgery). The performance of subjects with perirhinal-entorhinal damage provided an important comparison for subjects with specific hippocampal lesions. Despite showing intact memory for the remotely learned problem, perirhinal-entorhinal damage resulted in numerically (although not significantly) weaker performance on postoperative tests of retention for the discriminations learned in the 3 weeks prior to surgery. In the anterograde portion of the study, long-term memory for newly acquired discriminations was spared in subjects with damage to the hippocampus, whereas subjects in the perirhinal-entorhinal lesion group again showed the weakest memory performance on these tests of 5-day retention. Postoperative water maze learning was uniformly impaired in subjects with damage to the hippocampus and perirhinal-entorhinal cortex, thus confirming the effect of these lesions and supporting the involvement of these brain areas in spatial processes. These findings further dissociate the specific involvement of the hippocampus in tasks of a spatial-relational nature versus nonrelational tasks, such as discrimination learning and recognition memory (e.g., Duva et al., 1997; Eichenbaum, 1997; Eichenbaum, Schoenbaum, Young, & Bunsey, 1996). Moreover, the results suggest that damage to the hippocampus itself does not contribute to retrograde or anterograde memory impairments for all types of information, whereas the data suggest a more important role for the perirhinal-entorhinal cortex in recognition memory, irrespective of modality.
通过使用一种新颖的嗅觉引导范式和传统的空间学习测试，研究了海马系统在逆行性和顺行性遗忘中的作用。在逆行性研究中，大鼠在接受海马神经毒性损伤或嗅周 - 内嗅皮质吸出损伤前的几周内，接受一系列二选一嗅觉辨别训练。对术前学习的辨别的记忆测试表明，对于在手术时间较远（即4周以上）学习的问题或最近学习的两个辨别（即手术前1 - 3周），海马损伤的受试者没有统计学上的损伤。嗅周 - 内嗅皮质损伤的受试者的表现为特定海马损伤的受试者提供了重要的对照。尽管对远程学习的问题表现出完整的记忆，但嗅周 - 内嗅皮质损伤导致在手术后对手术前3周内学习的辨别的保持测试中的表现数值上（尽管不显著）较弱。在研究的顺行性部分，海马损伤的受试者对新获得的辨别的长期记忆得以保留，而嗅周 - 内嗅皮质损伤组的受试者在这些5天保持测试中再次表现出最弱的记忆表现。海马和嗅周 - 内嗅皮质损伤的受试者术后水迷宫学习均受到一致损害，从而证实了这些损伤的影响，并支持这些脑区参与空间过程。这些发现进一步区分了海马在空间关系性质的任务与非关系任务（如辨别学习和识别记忆，例如Duva等人，1997年；Eichenbaum，1997年；Eichenbaum、Schoenbaum、Young和Bunsey，1996年）中的特定参与情况。此外，结果表明，海马本身的损伤并非对所有类型的信息都导致逆行性或顺行性记忆损害，而数据表明嗅周 - 内嗅皮质在识别记忆中发挥更重要的作用，无论其方式如何。
