Hippocampus, amygdala, and memory deficits in rats

Five experiments were conducted to compare the contribution of the hippocampal formation and amygdala to mnemonic processes. The performance of rats with damage to the hippocampal formation or amygdala was examined in tests of visual and olfactory non-matching-to-sample with familiar items, cross-modal association, gustatory neophobia, topographical memory, autonomic conditioning to context, and configural discriminations. Neither lesion affects non-matching-to-sample performance. An intact hippocampal formation, but not amygdala, is necessary for cross-modal association between vision and olfaction, topographical memory, conditioning to context, and configural discrimination learning. Amygdala damage disrupted gustatory neophobia and may have impaired learning an association between an auditory cue and food reward.