Effects of Stress Coping Styles and Social Defeat on Zebrafish Behaviour and Brain Transcriptomics.

Individuals with divergent personality traits corresponding to stress coping styles have been suggested to differ in behavioural and neural plasticity. We used a model of social defeat stress to assess the coping ability of wild zebrafish selectively bred for boldness/shyness. Behavioural tests were applied to assess parameters such as boldness/exploration, aggressiveness, and displacement behaviour. Gene expression changes in the brain were assessed via RNA sequencing. The main results show a strong effect of shyness and boldness phenotype on behaviour and the brain transcriptome. Fish of the shy line displayed significant behavioural differences, while the number of differentially-expressed genes remained low. In contrast, fish of the bold line exhibited a small effect on behaviour and pronounced changes in brain gene expression. This study highlights the importance of boldness phenotype and its influence on the response to social challenges at the behavioural and transcriptomic levels.