The effects of hippocampectomy on performance by rats of a running recognition task using long lists of non-spatial items.
Unoperated rats, or rats with cortical control lesions or hippocampal aspiration lesions, were trained on a non-spatial delayed non-matching-to-sample task. Once the non-matching rule had been learned, the task was modified so as to assess list memory, with list lengths of up to 32 items. Hippocampectomy induced a significant drop in choice accuracy, that was independent of list length; nonetheless, hippocampectomised rats still performed at better than chance levels. The cortical control lesion appeared to induce an intermediate (though generally non-significant) deficit. It was concluded that hippocampectomy leaves rats still capable of choosing with considerable accuracy on non-spatial working memory tasks that use trial-unique or 'pseudo-trial-unique' stimuli, even under experimental conditions in which a heavy memory load is imposed.
Steele
K
K
University of Oxford, Department of Experimental Psychology, UK.
Rawlins
J N
JN
D000818:Animals; D001070:Appetitive Behavior / Q000502:physiology*; D001288:Attention / Q000502:physiology; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology; D004193:Discrimination Learning / Q000502:physiology*; D006624:Hippocampus / Q000502:physiology*; D008297:Male; D011939:Mental Recall / Q000502:physiology*; D009043:Motor Activity / Q000502:physiology*; D009949:Orientation / Q000502:physiology*; D051381:Rats; D012153:Retention, Psychology / Q000502:physiology; D012691:Serial Learning / Q000502:physiology*