After establishing that 15 days of repeated stress could successfully induce an anxiety disorder phenotype, we evaluated zebrafish brains for a few of the most common molecular markers of anxiety and related disorders reported in rodent models, such as corticotrophin-releasing factor (CRF), calcineurin and phospho CREB (cyclic AMP response element binding protein) [3], [29]. This evidence concerns the gene CREB1 and anxiety disorder.