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Research article - Peer-reviewed, 2020

Antidepressant exposure causes a nonmonotonic reduction in anxiety-related behaviour in female mosquitofish

Martin, Jake; Nagarajan-Radha, Venkatesh; Tan, Hung; Bertram, Michael; Brand, Jack A.; Saaristo, Minna; Dowling, Damian K.; Wong, Bob B.M.

Abstract

Worldwide, biologically active pharmaceuticals, such as psychoactive drugs, are routinely detected in aquatic ecosystems. In this regard, selective serotonin reuptake inhibitors (SSRIs), a class of antidepressant, are of major environmental concern. Through targeted action on evolutionarily conserved physiological pathways, SSRIs could alter ecologically important behaviours in exposed organisms. Here, using two field-realistic dosages (measured concentrations: 18 and 215 ng/L) of the SSRI fluoxetine (Prozac), we examined the effects of exposure on anxiety-related behaviours in wild-caught female mosquitofish, Gambusia holbrooki. Anxiety-related behaviour was assessed using a light/dark transition test, with the swimming activity of fish recorded under two alternating light conditions, complete darkness and bright light, with the shift in light condition used to induce an anxiety-like response. Fluoxetine exposure resulted in a nonmonotonic decrease in anxiety-related behaviour (i.e. nonlinear with dose), with fish in the low-fluoxetine treatment being less responsive to shifts in light condition compared to unexposed fish. There was no such difference between unexposed and high-exposed fish. Further, we detected a significant interaction between exposure treatment and fish weight on general swimming activity, suggesting the presence of a mass-specific effect of fluoxetine. More broadly, contaminant-induced disruption of animal behaviour—as documented here—could have wide-reaching effects on population-level fitness.

Keywords

Boldness; Fish; Fluoxetine; Light/dark transition; SSRI; Swimming activity

Published in

Journal of hazardous materials letters
2020, Volume: 1, article number: 100004

        SLU Authors

        UKÄ Subject classification

        Environmental Sciences
        Pharmacology and Toxicology

        Publication identifier

        DOI: https://doi.org/10.1016/j.hazl.2020.100004

        Permanent link to this page (URI)

        https://res.slu.se/id/publ/108199