Reexamination of functional subdivisions of the rodent prefrontal cortex

Selective patterns of behavioral deficits were observed on tests of spatial or olfactory learning after different cortical lesions in rats. The results clearly distinguished functional subdivisions of the rodent prefrontal cortex: Rats with lesions of the prefrontal cortex that primarily involve the dorsal bank of the rhinal sulcus were impaired selectively and exhibited increased perseveration of responses in a go, no-go odor discrimination task. In contrast, rats with lesions of the region of prefrontal cortex situated along the medial cortical wall were impaired selectively and exhibited increased perseveration of responses in a spatial delayed alternation task. These behavioral deficits were similar in magnitude and quality to those found in monkeys after discrete ablations of frontal lobe regions that are argued to be homologous preforontal subdivisions.