Environmentally relevant concentrations of triclocarban affect behaviour, learning, and brain gene expression in fish

Tyrone Lucon-Xiccato; Beste Başak Savaşçı; Carmine Merola; Elisabetta Benedetti; Giulia Caioni; Valbona Aliko; Cristiano Bertolucci; Monia Perugini

doi:10.1016/j.scitotenv.2023.166717

Environmentally relevant concentrations of triclocarban affect behaviour, learning, and brain gene expression in fish

Sci Total Environ. 2023 Dec 10:903:166717. doi: 10.1016/j.scitotenv.2023.166717. Epub 2023 Aug 30.

Authors

Tyrone Lucon-Xiccato¹, Beste Başak Savaşçı², Carmine Merola³, Elisabetta Benedetti⁴, Giulia Caioni⁴, Valbona Aliko⁵, Cristiano Bertolucci⁶, Monia Perugini³

Affiliations

¹ Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy. Electronic address: tyrone.luconxiccato@unife.it.
² Unit of Evolutionary Biology/Systematic Zoology, Institute for Biochemistry and Biology, University of Potsdam, Potsdam, Germany; Department of Bioscience and Agro-Food and Environmental Technology, University of Teramo, Teramo, Italy.
³ Department of Bioscience and Agro-Food and Environmental Technology, University of Teramo, Teramo, Italy.
⁴ Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy.
⁵ Department of Biology, Faculty of Natural Sciences, University of Tirana, Tirana, Albania.
⁶ Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy.

PMID: 37657536
DOI: 10.1016/j.scitotenv.2023.166717

Abstract

Many chemicals spilled in aquatic ecosystems can interfere with cognitive abilities and brain functions that control fitness-related behaviour. Hence, their harmful potential may be substantially underestimated. Triclocarban (TCC), one of the most common aquatic contaminants, is known to disrupt hormonal activity, but the consequences of this action on behaviour and its underlying cognitive mechanisms are unclear. We tried to fill this knowledge gap by analysing behaviour, cognitive abilities, and brain gene expression in zebrafish larvae exposed to TCC sublethal concentrations. TCC exposure substantially decreased exploratory behaviour and response to stimulation, while it increased sociability. Additionally, TCC reduced the cognitive performance of zebrafish in a habituation learning task. In the brain of TCC-exposed zebrafish, we found upregulation of c-fos, a gene involved in neural activity, and downregulation of bdnf, a gene that influences behavioural and cognitive traits such as activity, learning, and memory. Overall, our experiments highlight consistent effects of non-lethal TCC concentrations on behaviour, cognitive abilities, and brain functioning in a teleost fish, suggesting critical fitness consequences of these compounds in aquatic ecosystems as well as the potential to affect human health.

Keywords: Cognitive plasticity; Danio rerio; Fish behaviour; Learning; TCC.