Altered glucocorticoid reactivity and behavioral phenotype in rx3-/- larval zebrafish

Introduction The transcription factor rx3 is important for the formation of pituitary and parts hypothalamus. Mutant animals lacking function have been well characterized in developmental studies, but relatively little known about their behavioral phenotypes. Methods We used cell type staining to reveal differences stress axis architecture, performed cortisol measurements behavior analysis study both hormonal responses mutants. Results Discussion Consistent with role hypothalamus development, we show a distinct loss corticotrope cells involved regulation, severe reduction innervation by hypothalamic cells, lack stress-induced release Interestingly, despite these deficits, report that rx3-/- larval zebrafish can still display nominal stressful non-stressful stimuli. However, unlike wildtypes, mutants proper pituitary-interrenal do not enhanced performance under moderate level, supporting view corticotroph are required some types stimuli modulate subtle adjustments stress.