Role of the rodent hippocampus in paired-associate learning involving associations between a stimulus and a spatial location.

The ability of rats with control or hippocampal lesions to learn an object-place, odor-place, or object-odor paired-associate task was assessed in a cheeseboard maze apparatus. The data indicate that rats with hippocampal lesions were significantly impaired, compared with controls, in learning both the object-place and the odor-place paired-associate tasks. However, rats with hippocampal lesions learned the object-odor paired-associate task as readily as did controls. The data suggest that the rodent hippocampus is involved in paired-associate learning when a stimulus must be associated with a spatial location. However, the hippocampus is not involved in paired-associate learning when the association does not involve a spatial component.