Effects of Nicotine Administration, Cessation, and Differential Housing Conditions on Aggressive Behaviors of Male and Female Rats

摘要

The present experiment examined effects of nicotine administration, nicotine cessation, and two housing conditions (individuals vs. grouped) on social interaction and serum testosterone in Long-Evans rats. Nicotine reduced aggressive behavior of male and female rats, particularly in single-house conditions. Effects of nicotine on serum testosterone in males also depended on housing condition with nicotine reducing serum testosterone of single-housed males but not group-housed males. In addition, single-housed males and females exhibited more aggressive behaviors than group-housed animals. Male testosterone levels and aggressive behaviors returned to baseline during nicotine cessation. The results suggest that effects of nicotine may be modified by environmental or social situations. Further, for male subjects, aggressive behavior were accounted for by housing and drug conditions rather than by testosterone levels.