Behavior of male and female rats with septal lesions: Influence of prior gonadectomy

The influence of gonadectomy at different ages upon the behavioral changes induced by septal lesions in adulthood was examined in male and female rats. In both sexes septal lesions increased emotionality, facilitated acquisition of shuttle avoidance responding, increased escape from light onset, depressed rearing in the open field, increased the number of shocks received during passive avoidance acquisition, but did not affect the number of sessions required to acquire or to extinguish the passive avoidance response. In males prepuberal, but not neonatal or adult gonadectomy attenuated hyperemotionality, but gonadectomy had little influence on other behavioral changes produced by septal lesions. Ovariectomy, either prepuberally or in adulthood, also attenuated hyperemotionality in females with lesions. Adult, but not prepuberal ovariectomy rendered females with septal lesions somewhat hypoactive compared to other female groups. Among animals without lesions, females reared more, entered more squares and were less likely to defecate than males during open field tests. Neonatal, but not prepuberal or adult gonadectomy increased both rearing and activity in males. Females also acquired active avoidance behvior and extinguished passive avoidance behavior more rapidly than males and gonadectomy at any age did not abolish the sex differences in these behaviors. Sex differences in behavior and the effects of gonadectomy were generally similar in controls and in animals with septal lesions, suggesting that differences in septal function are not likely to underly sex differences in these behaviors.