TY - JOUR
T1 - The effect of cytotoxic lesions of the hippocampus on object recognition memory in the rat: effects of stimulus size
AU - Higgs, Suzanne
AU - Bannerman, DM
AU - Rawlins, JNP
PY - 2001/1/1
Y1 - 2001/1/1
N2 - Rats with excitotoxic hippocampal lesions were trained on delayed nonmatching-to-sample (DNMS) with small goal boxes, containing complex objects, presented on a pseudo trial-unique schedule. A series of experiments then tested performance on repeated presentation of either the small object or large empty goal boxes. All rats acquired the nonmatching rule, but hippocampal-lesioned rats performed less well than controls on choice accuracy for the final 2 blocks of acquisition. In the study's main phase, the lesions impaired choice accuracy when the large empty boxes were used as stimuli. This deficit was ameliorated when the rats were tested with the small object boxes, although the performance of the hippocampal-lesioned rats was still below that of controls. These results extend previous reports of box size-dependent effects of hippocampal aspiration lesions on DNMS and suggest that selective damage to the hippocampus, not neuronal loss in adjacent structures or fiber tracts, is critical for the effect.
AB - Rats with excitotoxic hippocampal lesions were trained on delayed nonmatching-to-sample (DNMS) with small goal boxes, containing complex objects, presented on a pseudo trial-unique schedule. A series of experiments then tested performance on repeated presentation of either the small object or large empty goal boxes. All rats acquired the nonmatching rule, but hippocampal-lesioned rats performed less well than controls on choice accuracy for the final 2 blocks of acquisition. In the study's main phase, the lesions impaired choice accuracy when the large empty boxes were used as stimuli. This deficit was ameliorated when the rats were tested with the small object boxes, although the performance of the hippocampal-lesioned rats was still below that of controls. These results extend previous reports of box size-dependent effects of hippocampal aspiration lesions on DNMS and suggest that selective damage to the hippocampus, not neuronal loss in adjacent structures or fiber tracts, is critical for the effect.
U2 - 10.1037/0735-7044.115.6.1193
DO - 10.1037/0735-7044.115.6.1193
M3 - Article
C2 - 11770051
VL - 115
SP - 1193
EP - 1203
JO - Behavioral Neuroscience
JF - Behavioral Neuroscience
ER -