Impaired recognition memory in rats after damage to the hippocampus.
Rats with radio-frequency or ibotenic acid lesions of the hippocampus and rats with radio-frequency lesions of the fornix were tested on the visual paired comparison task (VPC), a test of recognition memory. Memory was assessed at five different delay intervals ranging from 10 sec to 24 hr. All operated groups performed normally at the shorter delays (10 sec and 1 min). Across longer delays, the two groups with hippocampal damage were impaired. Rats with fornix lesions performed well on the VPC task but were impaired on a spatial task (spontaneous alternation). The results show that the hippocampus is essential for normal recognition memory. Moreover, fornix lesions need not mimic the effects of direct damage to hippocampal tissue. The findings are discussed in the context of the contribution of the hippocampus to recognition memory.
Clark
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Veterans Affairs Medical Center, San Diego, California 92161, USA. Clark@whoville.ucsd.edu
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Squire
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D000818:Animals; D017115:Catheter Ablation; D020712:Fornix, Brain / Q000473:pathology / Q000502:physiology* / Q000601:surgery; D006624:Hippocampus / Q000187:drug effects / Q000473:pathology / Q000502:physiology* / Q000601:surgery; D007051:Ibotenic Acid / Q000494:pharmacology; D008297:Male; D008568:Memory / Q000187:drug effects / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000187:drug effects / Q000502:physiology; D051381:Rats; D020318:Rats, Long-Evans; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D021641:Recognition, Psychology / Q000187:drug effects / Q000502:physiology; D012107:Research Design; D012680:Sensitivity and Specificity; D013037:Spatial Behavior / Q000187:drug effects / Q000502:physiology; D013997:Time Factors
D007051:Ibotenic Acid