Interindividual Variability in Swiss Male Mice: Relationship between Social Factors, Aggression, and Anxiety

• Published in: Physiology & behavior 1998-03, Vol.63 (5), p.821-827
• Main Authors: Ferrari, P.F, Palanza, P, Parmigiani, S, Rodgers, R.J
• Format: Article
• Language: English
• Subjects: Aggression; Aggression - psychology; Animal ethology; Animals; Anxiety; Anxiety - psychology; Arousal; Avoidance Learning; Biological and medical sciences; Coping strategies; Dominance-Subordination; Elevated plus-maze; Fundamental and applied biological sciences. Psychology; Hierarchy, Social; Individuality; Male; Mammalia; Maze Learning; Mice; Motor Activity; Psychology. Psychoanalysis. Psychiatry; Social Environment; Social experience; Social status; Swiss–Webster mice; Vertebrata
• ISSN: 0031-9384; 1873-507X
• DOI: 10.1016/S0031-9384(97)00544-1

In the present study we carried out a series of experiments in Swiss albino male mice to investigate a) the effects of previous social experience on the levels of anxiety in the elevated plus-maze (EPM) and b) whether the response of males in the EPM differs in relation to the different social status. In Experiment 1 we tested in the EPM male mice that received different social experience. Results showed that individually housing generally increased measures of anxiety in the EPM compared with the group-housing condition. Moreover, aggressive males, screened during dyadic encounters in a neutral cage, displayed the highest levels of anxiety relative to the other experimental conditions. In Experiment 2 male mice remained group-housed and were observed to record their social status. Results showed that those animals rated as socially dominant displayed a higher level of EPM anxiety relative to subordinates. From an ethological perspective our findings may be interpreted in terms of coping strategies, with aggressive/dominant animals typified by higher levels of risk assessment and open-arm avoidance than defensive/subordinate animals.