Prenatal treatment with picrotoxin promotes heterotypical sexual behavioral and neurochemical changes in male rat offspring

Abstract

The effects of maternal prenatal exposure to picrotoxin (0.75 mg/kg S.C. days 16–19 of pregnancy) in male rat offspring were observed. Adult sexually experienced and inexperienced animals were evaluated for heterotypical sexual behavior, as well as the testosterone plasma levels and striatal neurotransmitters. In relation to sexual behavior and analysis of sexual organs, the results showed that animals treated with picrotoxin exhibited a more intense reproductive behavior, and this could be expressed by a significant decrease in the number of mounts and intromissions and increase in the numbers of ejaculation, showed that these males are most motivate for sexual behavior. Testosterone levels as well as weight for sexual organs did not differ from control group. The neurochemical analysis showed that picrotoxin did not alter DA, 5-HT, 5-HIAA and GABA in animals. The DOPAC/DA and HVA/DA relation showed that the treatment increased the DA system activity in animals sexually experienced, as well as promote a decrease in 5-HT/5-HIAA relation, that is known was an inhibitory neurotransmitter system, blockade a male sexual behavior. There are no alterations observed in GABA levels. It's could be explained by suggests that picrotoxin modification DA system activity through GABAergic system, permitting that DA system to be freely active and facilitate the heterotypical behavior of male rats. These results show that the maternal prenatal exposure to picrotoxin produced changes in the neurochemical and sexual behavior of the adult male rats. Also previous heterotypical experience leads to changes in biogenic amine concentrations in these animals.