Developmental exposure to low concentrations of two brominated flame retardants, BDE-47 and BDE-99, causes life-long behavioral alterations in zebrafish
Autor: | Mamta Behl, Richard E. Galat, Lilah Glazer, Corinne Wells, Kathryn-Ann Odamah, Meghan Drastal, Edward D. Levin |
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Rok vydání: | 2018 |
Předmět: |
Male
Reflex Startle Embryonic Development Physiology 010501 environmental sciences Toxicology 01 natural sciences Article 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine Polybrominated diphenyl ethers Avoidance Learning Halogenated Diphenyl Ethers medicine Animals Habituation Zebrafish Flame Retardants 0105 earth and related environmental sciences Behavior Animal biology General Neuroscience Organophosphate Neurotoxicity medicine.disease biology.organism_classification chemistry Chlorpyrifos Toxicity Female Hypoactivity Locomotion 030217 neurology & neurosurgery |
Zdroj: | NeuroToxicology. 66:221-232 |
ISSN: | 0161-813X |
Popis: | Background Polybrominated diphenyl ethers (PBDEs) were widely used as flame retardants until the early 2000s, mainly in home furnishings and electronics. The persistence of PBDEs in the environment leads to continued ubiquitous exposure to low levels, with infants and children experiencing higher exposures than adults. Accumulating evidence suggest that low-level exposures during early life stages can affect brain development and lead to long-term behavioral impairments. We investigated the effects of zebrafish exposure to low doses of the two prominent PBDEs; 2,2′,4,4′,5,-Pentabromodiphenyl ether (BDE-99) and 2,2′,4,4′,-Tetrabromodiphenyl ether (BDE-47), during embryo-development on short- and long-term behavioral endpoints. We included the organophosphate pesticide chlorpyrifos (CPF) due to its well documented neurotoxicity across species from zebrafish to humans. Methods Zebrafish embryos were exposed to the following individual treatments; 0.1% DMSO (vehicle control); 0.3 μM CPF; 0.01, 0.03, 0.1, 0.3 μM BDE-47; 0.003, 0.03, 0.3, 1, 3, 10, 20 μM BDE-99 from 5 until 120 h post fertilization (hpf). Low exposure levels were determined as those not causing immediate overt toxicity, and behavior assays were conducted in the low-level range. At 144 hpf the larvae were tested for locomotor activity. At approximately 6 months of age adult zebrafish were tested in a behavioral battery including assays for anxiety-related behavior, sensorimotor response and habituation, social interaction, and predator avoidance. Results In the short-term, larval locomotor activity was reduced in larvae treated with 0.3 μM CPF and 0.1 μM BDE-47. BDE-99 treatment caused non-monotonic dose effects, with 0.3 μM causing hyperactivity and 1 μM or higher causing hypoactivity. In the long-term, adult anxiety-related behavior was reduced in all treatments as measured in both the novel tank dive test and tap test. Discussion We show that exposure of zebrafish embryos to low concentrations of the brominated flame retardants BDE-47 and BDE-99, and the organophosphate pesticide CPF, caused both short- and long-term behavioral impairments. Interestingly, we also found that at very low exposure concentrations, where there were no visible effects on larval activity, adult behavior was still strongly affected. |
Databáze: | OpenAIRE |
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