Treatment with corticosteroid receptor agonists in early life induces adulthood anxiety. (A) Timeline of drug-treated ELS and experiments conducted. A schematic diagram of the setup is presented below the timeline. (B) Representative swim paths of 60 dpf controls (DMSO) and hydrocortisone 21-hemisuccinate- (Cort) treated animals. Drug-treated individuals tend to spend more time at the bottom of the tank. (C) Total duration spent in the bottom zone of the novel tank was significantly increased in Cort animals (Unpaired t test, p = 0.0001), and decreased in the top (Unpaired t test, p = 0.0026) and middle (Unpaired t test, p = 0.0002) zones, compared to control DMSO. N = 17 per group. (D) Basal cortisol levels were significantly higher in Cort animals than control DMSO siblings (n = 6 per group, Unpaired t test, p = 0.038). (E) Representative swim paths of 60 dpf controls (DMSO) and dexamethasone- (Dex) treated animals. Drugtreated individuals tend to spend more time at the bottom of the tank. (F) Quantification of durations spent in top, middle, and bottom zones of the novel tank test revealed that Dex animals spent more time in the bottom zones (Unpaired t test, p = 0.025), and less time in the top (p = 0.035) than control DMSO animals yet no difference was observed in time spent in the middle (Unpaired t test, p = 0.11). DMSO: n = 38; Dex: n = 40. (G) Measurements of basal cortisol levels were no different between Dex and DMSO animals (n = 3 per group, Unpaired t test, p = 0.77). Error bars show ± standard error of the mean. Asterisks denote statistical significance (*p = 0.05, **p = 0.005, ***p = 0.0005). ns denotes no significance.
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