title: Evaluation of the neurotoxic effects of chronic embryonic exposure with inorganic mercury on motor and anxiety-like responses in zebrafish (Danio rerio) larvae.
abstract: Chronic exposure to mercury (Hg) can lead to cumulative impairments in motor and cognitive functions including alteration in anxiety responses. Although several risk factors have been identified in recent year, little is known about the environmental factors that either due exposure toward low level of inorganic mercury that may led to the developmental disorders. The present study investigated the effects of embryonic exposure of mercury chloride on motor function and anxiety-like behavior. The embryo exposed to 6 different concentrations of HgCl2(7.5, 15, 30, 100, 125, 250nM) at 5hpf until hatching (72hpf) in a semi-static condition. The mortality rate increased in a dose dependent manner where the chronic embryonic exposure to 100nM decreased the number of tail coiling, heartbeat, and swimming activity. Aversive stimulus was used to examine the effects of 100nM interferes with the development of anxiety-related behavior. No elevation in both thigmotaxis and avoidance response of 6dpf larvae exposed with 100nM were found. Biochemical analysis showed HgCl2exposure affects proteins, lipids, carbohydrates and nucleic acids of the zebrafish larvae. These results showed that implication of HgCl2on locomotor and biochemical defects affects motor performance and anxiety-like responses. Yet, the potential underlying mechanisms these responses need to be further investigated which is crucial to prevent potential hazards on the developing organism due to neurotoxicant exposure.
authors.affiliation: Department of Biology, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
authors.forename: Noraini
authors.initials: N
authors.lastname: Abu Bakar
authors.affiliation: Department of Biology, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
authors.forename: Nurul Syafida Asma'
authors.initials: NS
authors.lastname: Mohd Sata
authors.affiliation: Department of Biology, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
authors.forename: Nurul Farhana
authors.initials: NF
authors.lastname: Ramlan
authors.affiliation: Department of Biology, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia. Electronic address: wnwi@upm.edu.my.
authors.forename: Wan Norhamidah
authors.initials: WN
authors.lastname: Wan Ibrahim
authors.affiliation: Department of Biology, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
authors.forename: Syaizwan Zahmir
authors.initials: SZ
authors.lastname: Zulkifli
authors.affiliation: Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia; Institute of Advanced Technology (ITMA), Seri Kembangan, 43400 Serdang, Selangor, Malaysia.
authors.forename: Che Azurahanim
authors.initials: CA
authors.lastname: Che Abdullah
authors.affiliation: Department of Biochemistry, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
authors.forename: Syahida
authors.initials: S
authors.lastname: Ahmad
authors.affiliation: Department of Biology, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
authors.forename: Mohammad Noor Azmai
authors.initials: MN
authors.lastname: Amal
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D006339:Heart Rate / Q000187:drug effects; D007814:Larva / Q000187:drug effects*; D008628:Mercury / Q000633:toxicity*; D009043:Motor Activity / Q000187:drug effects*; D013550:Swimming; D015027:Zebrafish
chemical_list: D008628:Mercury
keywords: Anxiety; Hypolocomotion; Mercury chloride; Zebrafish