Differences in behavioral and physiological responses to stress in zebrafish

Throughout their lives, animals encounter stressors and often successfully over come them. Using recently-derived lines of zebrafish, one can observe the differences in both behavioral & physiological responses to stress. These differences help to characterize the different lines of zebrafish used in our lab. I tested whether (i) differences in behavior exist between two lines of zebrafish and (ii) levels of whole-body cortisol differ between stress coping styles through the use of the Novel Tank Diving Test (NTDT) and hormone assays. The Novel Tank Diving Test is an acute stressor and measures the amount of time spent in both the top and bottom half of the tank. To measure the amount of cortisol produced by each animal, tissue was homogenized, hormones extracted, and then measured in an enzyme immunoassay. The results show that shy animals spend more time in the lower portion of the NTDT than bold animals. Both bold and shy animals who went through the Novel Tank Diving Test (stressor) have higher cortisol levels than the control (non-stressed) zebrafish. Overall, these results create the basis for looking at the neuroendocrine mechanisms of alternative stress-related behaviors in zebrafish