Training method dramatically affects the acquisition of a place response in rats with neurotoxic lesions of the hippocampus.
A considerable number of studies have demonstrated that hippocampal damage impairs the acquisition of a place response in rats. In Experiment 1, using a four-arm plus-shaped maze, we replicated this finding. Experiment 2 showed, however, that hippocampally damaged rats can learn a place response just as well as control rats when, during the training, a salient intramaze landmark indicates the position of the goal (the west arm). After reaching criterion, the hippocampal and control groups performed the task with the same degree of mastery during a transfer test in which the intramaze signal used during the acquisition was removed. In Experiment 3, the intramaze cue was substituted by an egocentric cue. The results revealed that both control and lesioned subjects learned the spatial problem well. However, a transfer test showed that control rats learned the task using a place response strategy but hippocampally lesioned animals used a rigid, hyperspecific strategy. Taken together, these results suggest that special training procedures which encourage variability in response versus perseveration make it possible to overcome the acquisition deficit normally observed in hippocampal rats.
Ramos
Juan M J
JM
Departamento de Psicología Experimental y Fisiología del Comportamiento, Facultad de Psicología, Instituto de Neurociencias Federico Olóriz, Universidad de Granada, Spain. jmjramos@platon.ugr.es
D000818:Animals; D018891:Dentate Gyrus / Q000378:metabolism / Q000503:physiopathology; D006624:Hippocampus / Q000378:metabolism / Q000503:physiopathology*; D008297:Male; D018782:Maze Learning / Q000502:physiology; D009498:Neurotoxins / Q000378:metabolism*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D013028:Space Perception / Q000502:physiology; D013663:Teaching
D009498:Neurotoxins