Meeting Abstract
Dominance hierarchies resulting from repeated social interactions are common across the animal kingdom and have important consequences for reproduction and survival. Animals of lower social status cope with repeated social defeat using a variety of ‘active’ and ‘passive’ strategies. However, there remains a paucity of information on how an individual’s coping strategy changes over time or where this behavioral change may be controlled in the brain. We used a resident-intruder paradigm in the African cichlid fish Astatotilapia burtoni to investigate the neural correlates of repeated social defeat to the same aggressor, which better reflects the natural behavioral ecology of this lek-dwelling fish. We quantified aggressive behaviors performed by the resident, the intruder’s response (flee, hide, search, or no movement) to each behavior, and the amount of time the intruder spent ‘hiding’ or ‘searching’ for an escape, and then classified intruder behaviors as either passive or active using a principle component analysis. Passive (hiding, no attempt to flee, no aggressive behaviors performed) and active (searching, fleeing behaviors) coping behaviors were performed by all fish, and the individual variability in coping strategy depended on resident aggression. Despite this variability, all individuals increased their use of active coping on day 3 of repeated social defeat. To examine the neural correlates of this behavioral switch on day 3, we are quantifying immediate early gene expression in nuclei of the social decision-making network of animals collected on days 2, 3, and 4 of repeated social defeat. While variability in coping strategy is well documented, this is the first study to demonstrate temporal changes in coping mechanisms associated with social defeat in fishes and could reflect learned helplessness.
