THE INFLUENCE OF REPEATED EXPERIENCE OF A GGRESSION IN DAILY INTERMALE CONFRONTATIONS ON INDIVIDUAL AND SOCIAL-BEHAVIOR OF MALE-MICE

The influence of repeated experience of aggression in daily intermale confrontations on individual and social behaviour was studied in male mice of C57BL/6J (C57) and CBA/Lac (CBA) strains. Repeated experience of aggression led to a decrease of emotionality in males of highly emo tional CBA strain and increase in exploratory activity in the open fie ld and exploratory activity tests, decrease of immobility time in Pors olt's test and pain sensitivity estimated by the ''hot plate'' test, L ow emotional C57 males did not change their individual behaviour in di fferent situations under the influence of repeated experience of aggre ssion. However, aggressive C57 mice demonstrated anxiety-like behaviou r estimated in the plus-maze test. In the partition test aggressive mi ce of both strains showed an increase in communicative level (as a rea ction to a familiar male) in comparison with their behaviour before ag gressive confrontations. Behavioural reaction to a receptive female un der unfamiliar conditions decreased which testified to a decrease in s exual motivation. It is concluded that formation of the aggressive typ e of social behaviour is accompanied by changes in the individual and social behaviour of male mice. Characteristics of these changes are ge netically determined and depend on the duration of confrontations.