Stress effects on AVT and CRF systems in two strains of rainbow trout (Oncorhynchus mykiss) divergent in stress responsiveness

• Published in: Hormones and behavior 2011-01, Vol.59 (1), p.180-186
• Main Authors: Backström, Tobias, Schjolden, Joachim, Øverli, Øyvind, Thörnqvist, Per-Ove, Winberg, Svante
• Format: Article
• Language: English
• Subjects: Adaptation, Psychological - physiology; Analysis of Variance; Animal behavior; Animals; Arginine vasotocin (AVT); Behavioral psychophysiology; Biologi; Biological and medical sciences; Biology; Brain Stem - metabolism; Confinement stress; Corticotropin-releasing factor (CRF); Corticotropin-Releasing Hormone - genetics; Corticotropin-Releasing Hormone - metabolism; Cortisol; Enzyme-Linked Immunosorbent Assay; Fundamental and applied biological sciences. Psychology; Genetic diversity; Hormones and behavior; Hydrocortisone - blood; Hydroxyindoleacetic Acid - metabolism; Hypothalamic-pituitary-interrenal (HPI) axis; Monoamines; Motor Activity - physiology; NATURAL SCIENCES; NATURVETENSKAP; Neurobiology; Oncorhynchus mykiss; Oncorhynchus mykiss - genetics; Oncorhynchus mykiss - metabolism; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Receptors, Corticotropin-Releasing Hormone - genetics; Receptors, Corticotropin-Releasing Hormone - metabolism; RNA, Messenger - genetics; RNA, Messenger - metabolism; Serotonin - metabolism; Species Specificity; Statistics, Nonparametric; Steroids; Stress coping styles; Stress response; Stress, Physiological - physiology; Trout; Vasotocin - genetics; Vasotocin - metabolism
• ISSN: 0018-506X; 1095-6867; 1095-6867
• DOI: 10.1016/j.yhbeh.2010.11.008

The aim for this study was to examine whether the F4 generation of two strains of rainbow trout divergent in their plasma cortisol response to confinement stress (HR: high responder or LR: low responder) would also differ in stress-induced effects on forebrain concentrations of mRNA for corticotropin-releasing factor (CRF), arginine vasotocin (AVT), CRF receptor type 1 (CRF-R1), CRF receptor type 2 (CRF-R2) and AVT receptor (AVT-R). In addition, plasma cortisol concentrations, brainstem levels of monoamines and monoamine metabolites, and behaviour during confinement were monitored. The results confirm that HR and LR trout differ in their cortisol response to confinement and show that fish of these strains also differ in their behavioural response to confinement. The HR trout displayed significantly higher locomotor activity while in confinement than LR trout. Moreover, following 180min of confinement HR fish showed significantly higher forebrain concentrations of CRF mRNA than LR fish. Also, when subjected to 30min of confinement HR fish showed significantly lower CRF-R2 mRNA concentrations than LR fish, whereas there were no differences in CRF-R1, AVT or AVT-R mRNA expression between LR and HR fish either at 30 or 180min of confinement. Differences in the expression of CRF and CRF-R2 mRNA may be related to the divergence in stress coping displayed by these rainbow trout strains. ►HR and LR trout differ in plasma cortisol and locomotory activity during confinement. ►Forebrain CRF is higher in HR than LR trout after 180min of confinement. ►Forebrain CRF-R2 is lower in HR than LR trout after 30min of confinement.