Abstract
The isolation or individually-housed paradigm is one of the most frequently used in male mice, although animals submitted to this procedure show alterations in some behavioral and physiological variables. In this study, the level of aggression induced by isolation was compared with that induced by cohabitation with a female in OF1 male mice. After a period of four weeks of either isolation or cohabitation with a female, male mice were confronted with a non-aggressive opponent in a neutral area for 10 minutes. Encounters were videotaped and the behavior of animals was analyzed. The results showed that both paradigms induced the same level of aggression in this strain. Furthermore, no differences in other behaviors were found. This study suggests that cohabitation with a female is not only a more natural but also a valid paradigm to induce aggression in OF1 male mice.
