Effect of Arousal by Social Isolation, Grouping, and D-Amphetamine on Inter-Male Aggression in Mice (Mus Musculus)
24 adult male Swiss-Webster mice were randomly assigned to one of four equal experimental groups: a socially isolated group (8 days) which received a high dose of d-amphetamine prior to testing, a socially isolated group which received distilled water prior to testing, a social group of six (8 days) which received a high dose of d-amphetamine prior to testing, and a social group of six which received distilled water prior to testing. In the tests in which experimental animals were paired with stimulus animals which had their olfactory bulbs removed, inter-male aggression occurred even in the absence of aggressive retaliation by the stimulus animals. This suggests mutual arousal is sufficient to initiate and maintain biting attacks, aggressive retaliation is not necessary. Also, extremely high arousal in experimental mice induced by d-amphetamine and social isolation completely suppressed inter-male aggression whereas neither variable did so alone.