title: Effects of cadmium, manganese, and lead on locomotor activity and neurexin 2a expression in zebrafish.
abstract: The synaptic adhesion protein Neurexin 2a (Nrxn2a) plays a key role in neuronal development and is associated with cognitive functioning and locomotor behavior. Although low-level metal exposure poses a potential risk to the human nervous system, especially during the developmental stages, little is known about the effects of metal exposures on nrxn2a expression during embryonic development. We therefore exposed wild-type zebrafish embryos/larvae to cadmium (CdCl2), manganese (MnCl2), and lead ([CH3COO]2Pb), to determine their effect on mortality, malformation, and hatching rate. Concentrations of these metals in zebrafish were detected by inductively coupled plasma mass spectrometry analysis. Locomotor activity of zebrafish larvae was analyzed using a video-track tracking system. Expression of nrxn2a was assessed by in situ hybridization and quantitative polymerase chain reaction. The results showed that mortality, malformation, and bioaccumulation increased as the exposure dosages and duration increased. Developmental exposure to these metals significantly reduced larval swim distance and velocity. The nrxn2aa and nrxn2ab genes were expressed in the central nervous system and downregulated by almost all of the 3 metals, especially Pb. These data demonstrate that exposure to metals downregulates nrxn2a in the zebrafish model system, and this is likely linked to concurrent developmental processes. Environ Toxicol Chem 2017;36:2147-2154. © 2017 SETAC.
authors.affiliation: Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China.
authors.forename: Hongwei
authors.initials: H
authors.lastname: Tu
authors.affiliation: Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China.
authors.forename: Chengji
authors.initials: C
authors.lastname: Fan
authors.affiliation: Key Laboratory of Zebrafish Modeling and Drug Screening for Human Diseases of Guangdong Higher Education Institutes, Department of Developmental Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China.
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China.
authors.forename: Jiaxian
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.affiliation: Key Laboratory of Zebrafish Modeling and Drug Screening for Human Diseases of Guangdong Higher Education Institutes, Department of Developmental Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China.
authors.forename: Zhibin
authors.initials: Z
authors.lastname: Huang
authors.affiliation: Key Laboratory of Zebrafish Modeling and Drug Screening for Human Diseases of Guangdong Higher Education Institutes, Department of Developmental Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China.
authors.forename: Yiyue
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China.
authors.forename: Xiaojing
authors.initials: X
authors.lastname: Meng
authors.affiliation: Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, Guangdong, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Zou
mesh_terms: D000818:Animals; D002104:Cadmium / Q000378:metabolism / Q000633:toxicity*; D015536:Down-Regulation; D004357:Drug Synergism; D004625:Embryo, Nonmammalian / Q000002:abnormalities / Q000187:drug effects* / Q000378:metabolism; D047108:Embryonic Development / Q000187:drug effects / Q000235:genetics; D006023:Glycoproteins / Q000235:genetics*; D007814:Larva / Q000187:drug effects; D007854:Lead / Q000378:metabolism / Q000633:toxicity*; D008124:Locomotion / Q000187:drug effects*; D008345:Manganese / Q000378:metabolism / Q000633:toxicity*; D009479:Neuropeptides / Q000235:genetics*; D013550:Swimming; D015027:Zebrafish / Q000196:embryology / Q000235:genetics / Q000378:metabolism* / Q000502:physiology
chemical_list: D006023:Glycoproteins; D009479:Neuropeptides; C112162:neurexophilin; D002104:Cadmium; D007854:Lead; D008345:Manganese
keywords: Locomotor activity; Metal; Neurexin; Zebrafish