Figure 2. Chronic stress induces aggressor‐specific social avoidance.

Social interaction with a CD1 mouse used in the social defeat procedure was assessed in the social interaction test 1 day after the last stressor (A). Mice were additionally assessed for social preference (B) and recognition (C) with a conspecific mouse in the three‐chamber sociability test 1 week post stress. The social interaction test was non‐parametrically distributed and analysed using the Kruskal‐Wallis test. Significant differences are depicted as: ^* P < 0.05; Control compared to Stress. In the three‐chamber sociability test, differences between ‘object’ versus ‘mouse’ and ‘familiar mouse’ versus ‘novel mouse’ were assessed using a Student's unpaired t test. Significant differences are depicted as: ^* P < 0.05, ^** P < 0.01 and ^*** P < 0.001. All data are expressed as means ± SEM (n = 9–10). [Color figure can be viewed at http://wileyonlinelibrary.com]