Sex differences in measures of anxiety‐like behaviors following chronic intermittent ethanol and/or stress exposures using a zebrafish model system

Abstract

Studies on ethanol use have found that stress has a greater impact on responses in females than males. To improve our understanding of these differences, we used zebrafish to assess behavioral activities in male and female fish following treatment with chronic intermittent ethanol exposure and/or repeated stress exposure. Treatments were: Experiments A: once‐daily 30 min 1% ethanol and/or 3X 20 sec stress, or Experiments B: twice daily 30 min 1% ethanol and/or 3X 40 sec stress). We used a custom light/dark tank to assess behaviors at 24 hr after the final treatments. Zebrafish were tested individually on every 10 seconds, including light vs. dark preference, crossings between light and dark, preference for tank top vs. bottom and general activity levels (freezing or hyperactivity). Time spent in these activities were summated across the 8‐min testing period for each animal and averaged by sex within treatment condition. Overall, control females spent more in the dark (10–15%) for both sets of experiments compared to males. The milder treatments (Experiment A) found reduced time spent in the dark for females but not males, with Experiments B treatments significantly reducing time spent in the dark by 80% for ethanol and 55% for ethanol+stress in females. Only the Experiments B ethanol+stress condition reduced time in the dark, by 48% in males. Most of the additional Experiment A behavioral measures found an anxiolytic‐like effect for females, suggestive of resiliency, whereas the expanded treatments of Experiment B uncovered more anxiogenic‐like responses in females than males. Male zebrafish displayed greater increased levels of activity than females across treatment conditions, enhanced in Experiments B compared to Experiments A. These data support the utility of zebrafish as an animal model to study the impact of stress on ethanol responses and found that behavioral responses vary both by measure and by sex.Support or Funding InformationSupported by a PUSOP award to LLDThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.