Long-term dietary-exposure to non-coplanar PCBs induces behavioral disruptions in adult zebrafish and their offspring

Abstract

The use of polychlorinated biphenyls (PCBs) has been banned for several decades. PCBs have a long biological half-life and high liposolubility which leads to their bioaccumulation and biomagnification through food chains over a wide range of trophic levels. Exposure can lead to changes in animal physiology and behavior and has been demonstrated in both experimental and field analyses. There are also potential risks to high trophic level predators, including humans. A maternal transfer has been demonstrated in fish as PCBs bind to lipids in eggs. In this study, behavioral traits (exploration and free swimming, with or without challenges) of contaminated zebrafish (Danio rerio) adults and their offspring (both as five-day-old larvae and as two-month-old fish reared under standard conditions) were measured using video-tracking. Long-term dietary exposure to a mixture of non-coplanar PCBs was used to mimic known environmental contamination levels and congener composition. Eight-week-old fish were exposed for eight months at 26-28 °C. Those exposed to an intermediate dose (equivalent to that found in the Loire Estuary, ∑(CB)=515 ng g⁻¹ dry weight in food) displayed behavioral disruption in exploration capacities. Fish exposed to the highest dose (equivalent to that found in the Seine Estuary, ∑(CB)=2302 ng g⁻¹ dry weight in food) displayed an increased swimming activity at the end of the night. In offspring, larval activity was increased and two-month-old fish occupied the bottom section of the tank less often. These findings call for more long-term experiments using the zebrafish model; the mechanisms underlying behavioral disruptions need to be understood due to their implications for both human health and their ecological relevance in terms of individual fitness and survival.

Influence of sediment composition on PAH toxicity using zebrafish (Danio rerio) and Japanese medaka (Oryzias latipes) embryo-larval assays

“…Only a few studies have examined the impact of organic pollutant on the fish PMR. Using a similar approach, Péan et al (2013) reported a stimulation of this PMR following PCB contamination transferred to offspring zebrafish larvae. Furthermore, changes in zebrafish swimming rates, depending on PBDE congeners, have been shown by Usenko et al (2011).…”

“…Results were expressed as a percentage of all surviving larvae. response Behavioral tests were conducted to monitor photomotor response (PMR) following the procedure described by Péan et al (2013) with slight modifications. The day before analysis, 4-dpf larvae were acclimated individually in a 24-well plate (Krystal 24, transparent bottom, and opaque walls) with 2 mL of E3 medium in a climate chamber (28±0.5°C; 14-h light/10-h dark photoperiod).…”

Delayed effects of developmental exposure to low levels of the aryl hydrocarbon receptor agonist 3,3′,4,4′,5-pentachlorobiphenyl (PCB126) on adult zebrafish behavior

“…Furthermore, testing for behavioral endpoints in zebrafish can be performed from as early as the larval stages shortly after hatching, through the juvenile and adult stages, enabling accurate timing of phenotype occurrence and persistence. Although most of the zebrafish studies on the long-term effects of developmental chemical exposure have focused on adult behavior (Lee and Freeman, 2014b, Levin et al, 2003, Levin et al, 2011), a few investigators have taken advantage of the zebrafish model to look at neurobehavioral effects over multiple life-stages (Eddins et al, 2010, Pean et al, 2013). …”

Effects of embryonic exposure to polychlorinated biphenyls (PCBs) on anxiety-related behaviors in larval zebrafish

“…Continuous exposure to A1254 from immediately after fertilization until testing at 7dpf has also been found to disrupt performance on an optomotor assay consistent with impaired visual acuity (Zhang et al, 2015). Finally, offspring of adult zebrafish that had been exposed to a PCB mixture of 13 congeners for 8 months were found to be hyperactive at 5 dpf (Péan et al, 2013). …”