[Pro-aggressive effect of diazepam in male mice with repeated experience of aggression]

Previous studies have reported that repeated experience of aggression is attended with the development of increased anxiety in male mice. The paper aimed to investigate effect of anxiolytic, diazepam, on the level of anxiety and aggression in these animals. The drug was chronically administrated for two weeks at the process of aggression experience acquisition. It was shown that diazepam decreased anxiety but didn't influence aggression level assessed by total time of attacks. However, diazepam decreased demonstration of aggressive grooming in part of aggressive males. Group of diazepam-treated aggressive males which displayed aggressive grooming didn't differ in level of anxiety and aggression in saline-treated male mice. Diazepam had anxiolytic and pro-aggressive effects in male mice without demonstrating aggressive grooming. Thus, we can conclude that anxiolytic effect of diazepam is accompanied with increased aggression as side effect in some male mice which have repeated experience of aggression.