The effects of two types of frontal lesions on reversal learning and activity level in rats

The purpose of this experiment was to compare traditional frontal pole lesions (FP) with lesions of the median dorsal nucleus projection (MDNP) described by Leonard. First, a comparison was made on the retention of spatial discrimination learning and the new learning of spatial discrimination reversals between these two groups of frontally lesioned rats. It was hypothesized that the most severe deficits in spatial reversal learning would be shown in rats receiving MDNP lesions since this area of the rat cortex appears to be homologous to the frontal cortex of higher species according to Leonard’s results. Second, activity was measured on two post-operative occasions, before and after the reversal learning tasks, in both a familiar and an unfamiliar environment