Delayed-alternation performance after selective lesions of the medial and sulcal prefrontal cortex of the guinea pig.

The sulcal or medial subdivision of the prefrontal cortex of the guinea pig was ablated after the animals had learned a spatial delayed-alternation task. Retention of this task was significantly impaired only after ablation of the medial prefrontal cortex. As the most critical cortical region for delayed-alternation performance in the rat is also situated in the medial prefrontal cortex, our findings suggest a close functional correspondence of the prefrontal cortices of these rodent species.