Effects of hormone manipulations and exploration on sex differences in maze learning

Abstract

The maze learning ability of male rats castrated at birth, males and females treated with cyproterone acetate or sesame oil, and females treated with testosterone within the first 10 days postpartum was compared to that of nonmanipulated males and females (Experiment 1). Neonatal castration and injections of cyproterone acetate and testosterone were found to significantly reverse normal sex differences in maze learning. In Experiment 2, differences in gonadal hormone secretions and activities during adulthood on maze learning ability were assessed. It was found that gonadectomy did not significantly influence the performance of males and females. In Experiment 3, females were found to exhibit a greater tendency to explore and make irrelevant section entries on a maze that was problem free. It is suggested that differences in maze learning are more greatly influenced by brain sex than by subsequent gonadal hormone secretions during adulthood and are also due to the tendency of females to make more exploration-linked errors.