Polyhalogenated carbazoles (PHCZs) are dioxinlike emerging contaminants, but limited information exists on their neurotoxicity and mechanisms. This study employed zebrafish embryos to investigate the adverse effects of 3-bromocarbazole (3-BCZ), a typical PHCZ, exposure in their early life stages and found that the 120 h post fertilization (hpf)-median lethal concentration (LC 50 ) value of 3-BCZ in zebrafish larvae was 2.88 mg/L. The results revealed that 3-BCZ inhibited tail coiling at ≥0.06 mg/L, decreased hatchability at ≥2.88 mg/L, increased mortality and malformation rates at ≥1.44 mg/L, induced aryl hydrocarbon receptor effects and reduced body length at ≥0.58 mg/L, and inhibited behavior activities at ≥0.06 mg/L. Further mechanism investigations showed that 3-BCZ exposures repressed the motor neuron axon length via downregulating the mRNA transcription levels of α1-tubulin, Gap43, Syn2a, and shha, and decreased central nervous system neurogenesis via downregulating the mRNA transcription levels of elavl3, nrd, mbp, and gfap. Overall, 3-BCZ induces developmental neurotoxicity in zebrafish larvae at 0.06 mg/L (1/50 LC 50 ). Tail coiling activity at 24 hpf and swimming total distance at 120 hpf could be ideal indicators of 3-BCZ health risks in zebrafish. These findings provide valuable insights for health and ecological risk assessments of 3-BCZ and other PHCZs.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.