Impacts of chronic exposure to sublethal diazepam on behavioral traits of female and male zebrafish (Danio rerio)

Kun Chen; Min Wu; Chen Chen; Hai Xu; Xiangyang Wu; Xuchun Qiu

Ecotoxicology and Environmental Safety (Jan 2021)

Impacts of chronic exposure to sublethal diazepam on behavioral traits of female and male zebrafish (Danio rerio)

Kun Chen,
Min Wu,
Chen Chen,
Hai Xu,
Xiangyang Wu,
Xuchun Qiu

Affiliations

Kun Chen: Institute of Environmental Health and Ecological Security, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China
Min Wu: Institute of Environmental Health and Ecological Security, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China
Chen Chen: Institute of Environmental Health and Ecological Security, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China
Hai Xu: Institute of Environmental Health and Ecological Security, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China
Xiangyang Wu: Institute of Environmental Health and Ecological Security, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China
Xuchun Qiu: Institute of Environmental Health and Ecological Security, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China; Faculty of Agriculture, Kyushu University, Motooka 744, Nishi-ku, Fukuoka 819-0395, Japan; Corresponding author at: Institute of Environmental Health and Ecological Security, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China.

Journal volume & issue: Vol. 208
p. 111747

Abstract

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Residues of the psychoactive drug diazepam (DZP) may pose potential risks to fish in aquatic environments, especially by disrupting their behavioral traits. In this study, female and male zebrafish were subjected to chronic exposure (21 days) to sublethal doses (120 and 12 µg/L) of DZP, aimed to compare the characteristics of their behavioral responses to DZP exposure, and to investigate the possible links between those behavioral responses and variations in their brain γ-aminobutyric acid (GABA) and acetylcholinesterase (AChE) levels. Chronic exposure to DZP significantly decreased the swimming velocity and locomotor activity of both genders, indicating a typical sedative effect. Compared with males, whose locomotor activity was only significantly decreased by exposure to DZP for 21 days, females became hypoactive on day 14 (i.e., more sensitive), and they developed tolerance to the hypoactive effect induced by 120 μg/L DZP by day 21. Exposure to DZP significantly disturbed the behavioral traits related to social interactions in females but not in males. Those results indicate that DZP exhibits sex-dependent effects on the behaviors of fish. Moreover, exposure to DZP for 21 days significantly disturbed almost all of the tested behavioral traits associated with courtship when both genders were put together. Sex-dependent responses in brain GABA and AChE levels due to DZP exposure were also identified. Significant relationships between the brain GABA/AChE levels and some behavioral parameters related to locomotor activity were detected in females, but not in males.

Published in Ecotoxicology and Environmental Safety

ISSN: 0147-6513 (Print); 1090-2414 (Online)
Publisher: Elsevier
Country of publisher: United States
LCC subjects: Technology: Environmental technology. Sanitary engineering: Environmental pollution; Geography. Anthropology. Recreation: Environmental sciences
Website: https://www.journals.elsevier.com/ecotoxicology-and-environmental-safety

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