Discriminative avoidance learning in hippocampal and cortical rats: Acquisition rate, behavioral strategies, and long-term retention

Abstract

Facilitation of visually discriminated avoidance learning was observed in rats 1 week after they were lesioned in the dorsal hippocampus. While perseveration of a spatial strategy acquired during a pretraining session occurs in sham-operated and cortically lesioned controls, no such perseveration was observed in hippocampals. Elimination of the presurgical shaping session reduced the number of spatial strategies in all groups, but differences in trials to criterion and percentage of place strategies remained. Retesting the animals 3 weeks after training showed that hippocampals and corticals had poorer retention than did shams. There were no differences in retention of groups tested 24 h after training. The long-term retention deficit seems to be independent of the fact that hippocampals learn faster, since cortically lesioned animals also showed the memory deficit, compared with controls, even though they had as many training trials. The results are taken as a demonstration of lesion-induced anterograde amnesia in the rat.

Abnormal learning and forgetting of individual spatial reversal problems in brain-damaged rats

“…results has been reported in hippocampal-lesioned rodents tested on a visual discrimination (Sara & David-Remacle, 1981) and a passive avoidance (Zornetzer et al, 1977) habit. ]…”

“…Sara and David-Remacle (1981) have reported that hippocampal-lesioned rats show defective retention of a visual discrimination habit without showing defective learning. A similar pattern of results has been reported by Zornetzer, Gold, and Boast (1977) in connection with learning and retention of a passive avoidance task in hippocampal-lesioned mice.…”

Entorhinal-hippocampal connections and object memory in the rat: acquisition versus retention

“…The dissociation between the acquisition and retention of object discriminations demonstrated by angular bundle animals stands in contrast to the more global deficits seen in rats with hippocampal damage on traditional spatial measures of memory. For example, rats with hippocampal lesions are impaired on both the acquisition and long-term retention of spatial information (Sara and David-Remacle, 1981;Peinado-Manzano, 1990). That hippocampal lesions lead to both acquisition and retention impairments on measures of spatial memory likely reflects the declarative nature of this information (Squire, 1992).…”

Impaired visual and spatial reversal learning in brain-damaged rats: Additional components of the “general learning system” of the rodent brain

“…Such a facilitative effect has recently been observed by Sara and David-Remacle (1981) in hippocampally lesioned rats and by Thompson (1982a) in mammillary-body-lesioned rats . The present study disclosed that anterior-thalamic-lesioned rats learn a white-black discrimination problem faster than do controls.…”