Involvement of the prelimbic-infralimbic areas of the rodent prefrontal cortex in behavioral flexibility for place and response learning

The present experiments investigated the role of the prelimbic-infralimbic areas in behavioral flexibility using a place-response learning paradigm. A ll rats received a bilateral cannula implant aimed at the prelimbic-infrali mbic areas. To examine the role of the prelimbic-infralimbic areas in shift ing strategies, rats were tested on a place and a response discrimination i n a cross-maze. Some rats were tested on the place version first followed b y the response version. The procedure for the other rats was reversed. Infu sions of 2% tetracaine into the prelimbic-infralimbic areas did not impair acquisition of the place or response discriminations. Prelimbic-infralimbic inactivation did impair learning when rats were switched from one discrimi nation to the other (cross-modal shift). To investigate the role of the pre limbic-infralimbic areas in intramodal shifts (reversal learning), one grou p of rats was tested on a place reversal and another group tested on a resp onse reversal. Prelimbic-infralimbic inactivation did not impair place or r esponse intramodal shifts. Some rats that completed testing on a particular version in the cross-modal and intramodal experiments were tested on the s ame version in a new room for 3 d. The transfer tests revealed that rats us e a spatial strategy on the place version and an egocentric response strate gy on the response version. Overall, these results suggest that the prelimb ic-infralimbic areas are important for behavioral flexibility involving cro ssmodal but not intramodal shifts.