Effects of amygdaloid and amygdaloid-hippocampal lesions on object recognition and spatial working memory in rats.
Neurotoxic lesions of the amygdala did not affect the postoperative acquisition of a nonspatial test of object recognition (delayed nonmatching to sample) even when retention delays were increased from 0 s to 20 or 60 s, or when test stimuli were deliberately repeated within a session. Although these amygdaloid lesions did not alter forced-choice spatial alternation, they slightly increased neophobic responses to novel foods and environments. In contrast, combined amygdalohippocampal (A + H) lesions impaired performance on the object recognition task when the retention intervals were increased beyond 0 s and when test stimuli were repeated within a session. The A + H rats were also severely impaired on the spatial alternation task, and they showed reduced neophobia. Comparisons with a previous study show that damage to the amygdala or hippocampus does not affect object recognition, whereas A + H damage produces clear deficits.
Aggleton
J P
JP
University of Durham, England.
Blindt
H S
HS
Rawlins
J N
JN
D000679:Amygdala / Q000502:physiology*; D000818:Animals; D001143:Arousal / Q000502:physiology; D001288:Attention / Q000502:physiology*; D001931:Brain Mapping; D004193:Discrimination Learning / Q000502:physiology*; D005518:Food Preferences / Q000502:physiology; D005556:Form Perception / Q000502:physiology*; D006624:Hippocampus / Q000502:physiology*; D008297:Male; D008568:Memory; D011939:Mental Recall / Q000502:physiology*; D009043:Motor Activity / Q000502:physiology; D009434:Neural Pathways / Q000502:physiology; D009474:Neurons / Q000502:physiology; D009949:Orientation / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology*; D051381:Rats; D011930:Reaction Time / Q000502:physiology; D012153:Retention, Psychology / Q000502:physiology; D012931:Social Environment