Characterization of stress-inducing conditions used to assess metabolic disorders in adult zebrafish

Increased utilization of smartphones and social media elicits a variety of health concerns, including increased stress. Specifically, cortisol levels are elevated in adolescents who frequently browse social media. Cortisol reduces circulating leptin, a hormone that signals satiety. While it has been previously demonstrated that cortisol reduces the ability for leptin to cross the blood-brain barrier, the molecular mechanisms of this regulatory axis are incompletely understood. Our study aims to characterize the physiological consequences of high stress conditions in adult zebrafish, such that this model organism can be used to untangle interactions between leptin and cortisol. We report that cortisol levels are higher in fish fed a high fat diet, which is consistent with studies from other research groups. We are currently exploring alternative conditions to elevate cortisol in zebrafish. Movement tracking data is being collected from fish exposed to blue light and manual agitation (chasing fish with an aquarium net). Preliminary data suggests that blue light exposure elicits the strongest stress response, with fish freezing in one position. Mucus cortisol and plasma leptin levels will also be obtained from fish exposed to these stressors. Tissues will be collected for expression analysis of gluconeogenic genes, as we begin to characterize stress effects at the liver. We hypothesize that in conditions where cortisol is high and leptin is low, expression of gluconeogenic genes will increase. This study will help us identify conditions that spike cortisol and will enable us to further assess the cortisol-leptin regulatory axis. Overall, we aim to expand the growing body of data highlighting zebrafish as a model system to assess molecular mechanisms of metabolic disease. This research is supported by internal funds through Northern State University. This abstract was presented at the American Physiology Summit 2026 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.