Stress Coping Style Alters Functional Brain Network Activity to Acute Stressor

Abstract

Consistent individual differences in behavior (e.g., personality types, stress coping styles) are a common occurrence across animal taxa. One hypothesis poses that the resulting constraints for within-individual behavioral variation may also lead to constraints for the evolution of behavior. With stress coping styles seen across taxa, it suggests a common underlying proximate mechanism. In this study we investigated neural activity patterns across the brain by quantifying immediate early gene expression in individuals with alternative stress coping styles in response to an acute stressor in zebrafish (Danio rerio). While immediate early gene expression levels of individual brain regions in the aversive brain network were similar across groups, functional network activity differed. There were several differences across groups including interactions between the basolateral amygdala and hippocampal homologs. One brain area that had many different connections across groups was the central gray. There were many differences involving central gray activity between proactive and reactive fish at baseline suggesting that baseline activity may prime for the reaction to stress. Collectively, baseline brain activity can predict behaviors, suggesting that these differences in brain interactions at baseline may be important for biasing behavioral responses to stressors that characterizes a stress coping style. Significance StatementIt is well known that individuals cope with stress in different ways but the underlying mechanisms are not well understood. In this study we investigate how different brain regions interact under stress in animals of different stress coping styles. We investigated activity patterns across several brain regions in fish with a passive or active response to stress. We used an innovative statistical method that allowed us to compare how the brain regions function together under stress. The central gray was the most different between proactive and reactive groups, suggesting that this region is important for biasing the response to stressors. Further baseline functional connectivity differed the most between groups, suggesting that activity at baseline is important for biasing the response to stress mainly through connections with the central gray. Ultimately, functional neural network activity better explains stress behaviors than individual brain activity.