Retrograde amnesia after hippocampal damage: Recent vs. remote memories in two tasks

• Published in: Hippocampus 2001, Vol.11 (1), p.27-42
• Main Authors: Sutherland, Robert J., Weisend, Michael P., Mumby, Dave, Astur, Robert S., Hanlon, Faith M., Koerner, Amy, Thomas, Michael J., Wu, Ying, Moses, Sandra N., Cole, Carrie, Hamilton, Derek A., Hoesing, Janice M.
• Format: Article
• Language: English
• Subjects: Amnesia, Retrograde - pathology; Amnesia, Retrograde - physiopathology; Animals; consolidation; Discrimination Learning - physiology; Hippocampus - pathology; Memory - physiology; place learning; Rats; relational configural visual discrimination; retrograde amnesia; Space Perception - physiology; spatial retrieval
• ISSN: 1050-9631; 1098-1063
• DOI: 10.1002/1098-1063(2001)11:1<27::AID-HIPO1017>3.0.CO;2-4

We review evidence from experiments conducted in our laboratory on retrograde amnesia in rats with damage to the hippocampal formation. In a new experiment reported here, we show that N‐methyl‐D‐aspartate (NMDA)‐induced hippocampal damage produced retrograde amnesia for both hidden platform and two‐choice visible platform discriminations in the Morris water task. For both problems there was a significant trend for longer training‐surgery intervals to be associated with worse retention performance. Little support is offered by our work for the concept that there is a process involving hippocampal‐dependent consolidation of memories in extrahippocampal permanent storage sites. Long‐term memory consolidation may take place within the hippocampus. The hippocampus may be involved permanently in storage and/or retrieval of a variety of relational and nonrelational memories if it was intact at the time of learning, even involving information which is definitely not affected in anterograde amnesia after hippocampal damage. Hippocampus 2001;11:27–42. © 2001 Wiley‐Liss, Inc.