Effects of chronic exposure to bisphenol-S on social behaviors in adult zebrafish: Disruption of the neuropeptide signaling pathways in the brain

Bisphenol S (BPS), considered to be a safe alternative to Bisphenol A, is increasingly used in a wide variety of consumer and industrial products. However, mounting evidence suggests that BPS can act as a xenoestrogen targeting a wide range of neuro-endocrine functions in animals. At present, very little is known about the impacts of BPS on social behaviors and/or the potential underlying mechanisms. To this end, we exposed adult male and female zebrafish to environmentally relevant concentrations of BPS (0 (control), 1, 10, and 30 mu g/L), as well as to 17 beta-estradiol (E2; 1 mu g/L; as positive control) for 75 days. Subsequently, alterations in social behaviors were evaluated by measuring shoal cohesion, group preferences, and locomotor activity. Furthermore, to elucidate the possible molecular mechanism underlying the neuro-behavioral effects of BPS, we also quantified the changes in the mRNA abundance of arginine vasotocin (AVT), isotocin (IT), and their corresponding receptors in the zebrafish brain. The results showed that E2 and BPS (30 mu g/L) decreased shoal cohesion in both males and females. Moreover, a marked decline in group preferences was observed in all treatment groups, while locomotor activity remained unaffected. Alterations in the social behaviors were associated with sex-specific changes in the mRNA expression of genes involved in IT and AVT signaling. Taken together, the results of this study suggest that chronic exposure to BPS can impair zebrafish social behaviors via disruption of isotocinergic and vasotocinergic neuro-endocrine systems. (C) 2020 Elsevier Ltd. All rights reserved.