Effects of postoperative environment on recovery of function after fimbria-fornix transection in the rat.
We have previously found that rats given dorsal hippocampus lesions show reduced deficits on maze learning, spontaneous alternation and extinction tasks when housed postoperatively in an "enriched" as opposed to an "impoverished" environment. In contrast, postoperative enriched conditions were ineffective in rats given bilateral entorhinal cortex lesions. In this study, we examined whether postoperative differential housing would reduce the impairment in radial maze performance induced by fimbria-fornix transections. Significant interactions were found between lesion state and housing condition for the total number of errors made, the number of errors on the first eight arms visited and for the number of arms visited before the first error in an 8-arm maze. The interaction was due to the fact that, in sham-operated rats, isolated ones made more errors than enriched counterparts whereas, in rats with lesions, enriched ones showed no improvement of performance in comparison to isolated counterparts. These data suggest that the integrity of fimbria-fornix pathways is an important factor for the expression of facilitated maze performance in intact enriched rats and in enriched rats with hippocampal system damage.
Kelche
C
C
Laboratoire de Neurobiologie des Comportements, Université Louis Pasteur, Strasbourg, France.
Dalrymple-Alford
J
J
Will
B
B
D000818:Animals; D006624:Hippocampus / Q000502:physiology* / Q000601:surgery; D007858:Learning; D008297:Male; D009949:Orientation; D051381:Rats; D013997:Time Factors