Effects of Positive and Negative Fighting Experiences on Behaviour in Adult Male Mice

Although it is well-established that repeated exposure to positive or negative fighting experience has profound effects on hormone production and neurotransmitter turnover in rats and mice, there are relatively few studies in which the effects of such treatments have been assessed on behaviour. Experience of social aggression leading to a victory augments attack in subsequent encounters of the same kind whereas experience of defeat has the opposite effect 2–8 . The focus of such studies has, however, been narrowly on threat and attack and most workers have merely considered the effects of an immediately preceding experience on subsequent behaviour. As it seems likely that animals accumulate a variety of positive and negative experiences and as detailed ethological methodologies were available, it seemed of utility to determine whether the effects of positive fighting experiences influenced more than just the propensity to attack and modified behaviour assessed somewhat distantly from the focus encounter.