title: A comparison of the effects of fimbria-fornix, hippocampal, or entorhinal cortex lesions on spatial reference and working memory in rats: short versus long postsurgical recovery period.
abstract: Using a radial maze task and different postoperative recovery periods, this experiment assessed and compared the reference and working memory performances of adult Long-Evans male rats subjected to entorhinal cortex, fimbria-fornix, and hippocampus lesions. Sham-operated rats were used as controls. In order to see whether the duration of the postsurgical recovery period would influence acquisition of the complex radial maze task, training began 1 month following surgery (Delay 1) for half the rats in each group, while for the other half training was started 6.5 months following surgery (Delay 2). The results indicated that at both recovery periods the entorhinal cortex lesions failed to affect either working or reference memory in the spatial task. Conversely, both fimbria-fornix and hippocampus lesions impaired both reference and working memory. While the reference memory deficit was generally similar in both fimbria-fornix and hippocampal lesion groups, analysis of the results for working memory indicated that at the longer delay rats with fimbria-fornix lesions were still impaired but in animals that had the hippocampus removed, working memory did not differ from that of controls. These results suggest that there was some recovery in those rats with hippocampal lesions (e.g., on the working memory task) but both hippocampal and fimbria-fornix animals were still impaired compared to controls when training was delayed 6.5 months following the operations.
authors.affiliation: Laboratoire de Neurosciences Comportementales et Cognitives, Université Louis Pasteur, UMR 7521 ULP/CNRS, 12 rue Goethe, F-67000 Strasbourg, France.
authors.forename: Rodrigue
authors.initials: R
authors.lastname: Galani
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Obis
authors.forename: Etienne
authors.initials: E
authors.lastname: Coutureau
authors.forename: Len
authors.initials: L
authors.lastname: Jarrard
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Cassel
mesh_terms: D000818:Animals; D018728:Entorhinal Cortex / Q000502:physiology* / Q000601:surgery*; D020712:Fornix, Brain / Q000502:physiology* / Q000601:surgery*; D006624:Hippocampus / Q000502:physiology* / Q000601:surgery*; D008297:Male; D008568:Memory / Q000502:physiology*; D011184:Postoperative Period; D051381:Rats; D020318:Rats, Long-Evans; D013028:Space Perception / Q000502:physiology*; D013997:Time Factors