Institute of Environmental Health and Ecological Security, College of Environment and Safety Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China; Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment, Suzhou University of Science and Technology, Suzhou 215009, China.
Institute of Environmental Health and Ecological Security, College of Environment and Safety Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China.
Aquat Toxicol. 2024 Jun;271:106921. doi: 10.1016/j.aquatox.2024.106921. Epub 2024 Apr 8.
Thimerosal (THI) is the most widely used form of organic mercury in pharmaceutical and personal care products, and has become a major source of ethylmercury pollution in aquatic ecosystems. However, knowledge about its potential risk to aquatic species is limited. In this study, zebrafish were exposed to THI for 7 days, and variations in their behavioral traits, brain monoaminergic neurotransmitter contents, and related gene expression were investigated. After the 7-day exposure, THI reduced locomotor activity and thigmotaxis in males but not females. Exposure to THI increased the social interaction between females but decreased that between males. The THI exposure also significantly reduced the serotonin (5-HT), 5-hydroxyindoleacetic acid, dopamine (DA), and 3,4-dihydroxyphenylacetic acid contents in the brain of males, but only significantly decreased the DA content in females. Correlation analysis revealed that the neurochemical alterations in the brain of zebrafish play critical roles in the behavioral abnormalities induced by THI exposure. Moreover, THI also significantly altered the expression of some genes associated with the synthesis, metabolism, and receptor binding of 5-HT and DA in the brain of zebrafish. The differences in these gene expressions between female and male zebrafish exposed to THI seem to be an important mechanism underlying their sex-specific responses to this chemical. This is the first report on the sex-specific effects of THI on behaviors and brain monoaminergic neurotransmitter contents in zebrafish, which can further improve our understanding of its toxic effects on teleost.
硫柳汞（THI）是医药和个人护理产品中最广泛使用的有机汞形式，已成为水生生态系统乙基汞污染的主要来源。然而，关于其对水生物种潜在风险的知识有限。在这项研究中，研究人员将斑马鱼暴露于 THI 中 7 天，研究其行为特征、脑单胺神经递质含量和相关基因表达的变化。经过 7 天的暴露，THI 降低了雄性斑马鱼的运动活性和触壁行为，但对雌性斑马鱼没有影响。暴露于 THI 增加了雌性斑马鱼之间的社交互动，但减少了雄性斑马鱼之间的社交互动。THI 暴露还显著降低了雄性斑马鱼大脑中的血清素（5-HT）、5-羟吲哚乙酸、多巴胺（DA）和 3,4-二羟基苯乙酸含量，但仅显著降低了雌性斑马鱼大脑中的 DA 含量。相关性分析表明，斑马鱼大脑中的神经化学变化在 THI 暴露引起的行为异常中起关键作用。此外，THI 还显著改变了与 5-HT 和 DA 合成、代谢和受体结合相关的一些基因在斑马鱼大脑中的表达。暴露于 THI 的雌性和雄性斑马鱼之间这些基因表达的差异似乎是其对这种化学物质产生性别特异性反应的重要机制。这是关于 THI 对斑马鱼行为和脑单胺神经递质含量的性别特异性影响的首次报道，可进一步提高我们对其对硬骨鱼毒性作用的理解。
