Behaviour 2019
Impacts of Repeated Social Defeat on Behavior and the Brain in an African Cichlid Fish  
Rose Wayne, Ava Karam, Karen Maruska. Louisiana State University, Baton Rouge, LA, United States

Chronic social defeat often results in groups of individuals that are susceptible (adopt avoidance and submissive behaviors) or resilient (unaffected), with associated differences in neural signatures in the brain. However, little is known about the neural mechanisms of coping behaviors. Using a novel resident-intruder social defeat paradigm in a species that naturally experiences defeat, A. burtoni, we tested the hypothesis that repeated social defeat influences future social behaviors, and that exclusive use of reactive coping behaviors (freezing, submission) in susceptible individuals after repeated defeat is maintained over time. Behavioral data shows that experimental fish can be grouped into resilient and susceptible behavioral categories. Using the activation marker, pS6, we reveal differences in neural activation patterns between susceptible fish displaying retained reactive behaviors after future contests compared to resilient fish displaying mixed reactive and proactive behaviors. Understanding the neural mechanisms that lead to maintenance of a fixed reactive coping strategy over time provides insight for understanding social stress and resilience across vertebrates.