Dissociation of the Medial Prefrontal, Posterior Parietal, and Posterior Temporal Cortex for Spatial Navigation and Recognition Memory in the Rat

Abstract

Rats with lesions of the medial prefrontal, posterior parietal, or posterior temporal cortex were tested in five spatial navigation tasks, which varied in egocentric or allocentric demands, a visual discrimination task, and two delayed nonmatching-to-sample tasks. Rats with prefrontal lesions were impaired at every spatial navigation task, whereas rats with posterior parietal lesions had selective spatial navigation impairments. Rats with prefrontal lesions were also impaired at a visual delayed nonmatching-to-sample task, as they were unable to learn the task, even with no delay. The results are consistent with the idea that the basic plan of mammalian cortex includes prefrontal, posterior parietal, and posterior temporal regions, each of which have generally similar functions across mammalian taxa. There are, however, species-typical differences that reflect specific ecological pressures on the development of the different regions.