Association between experience of aggression and anxiety in male mice

The sensory contact technique increases aggressiveness in male mice and allows an aggressive type of behavior to be formed as a result of repeated experience of social victories in daily agonistic confrontations. In the low aggressive and high emotional mice of CBA/Lac strain, repeated positive fighting experience leads to increased plus maze anxiety in the winners after 10 days of experience of victories and much more after 20 days. Behavioral reactivity to other conspecifics was significantly increased as revealed by the parameters of partition test, which measures aggressive motivation in the winners. Thus, anxiety as a consequence of repeated experience of aggression is associated with the increase of aggressive motivation in CBA/Lac mice. It is concluded, that: (1) Repeated experience of aggression provokes the development of anxiety in male mice. (2) The level of anxiety as well as its behavioral realization depends on the duration of aggressive experience and genetic strain. Genetically defined features of innate anxiety (trait or state) in individuals may determine the kind of association between aggressive experience, aggressive motivation and anxiety.