Department of Biology and CESAM, University of Aveiro, Aveiro 3810-193, Portugal.
Science Division, Canadian Light Source Inc., Saskatoon, Canada; Department of Anatomy and Cell Biology, University of Saskatchewan, Saskatoon, Canada.
Biochim Biophys Acta Gen Subj. 2019 Dec;1863(12):129298. doi: 10.1016/j.bbagen.2019.01.020. Epub 2019 Feb 12.
Neuronal and sensory toxicity of mercury (Hg) compounds has been largely investigated in humans/mammals with a focus on public health, while research in fish is less prolific and dispersed by different species. Well-established premises for mammals have been governing fish research, but some contradictory findings suggest that knowledge translation between these animal groups needs prudence [e.g. the relative higher neurotoxicity of methylmercury (MeHg) vs. inorganic Hg (iHg)]. Biochemical/physiological differences between the groups (e.g. higher brain regeneration in fish) may determine distinct patterns. This review undertakes the challenge of identifying sensitive cellular targets, Hg-driven biochemical/physiological vulnerabilities in fish, while discriminating specificities for Hg forms.
A functional neuroanatomical perspective was conceived, comprising: (i) Hg occurrence in the aquatic environment; (ii) toxicokinetics on central nervous system (CNS)/sensory organs; (iii) effects on neurotransmission; (iv) biochemical/physiological effects on CNS/sensory organs; (v) morpho-structural changes on CNS/sensory organs; (vi) behavioral effects. The literature was also analyzed to generate a multidimensional conceptualization translated into a Rubik's Cube where key factors/processes were proposed.
Hg neurosensory toxicity was unequivocally demonstrated. Some correspondence with toxicity mechanisms described for mammals (mainly at biochemical level) was identified. Although the research has been dispersed by numerous fish species, 29 key factors/processes were pinpointed.
Future trends were identified and translated into 25 factors/processes to be addressed. Unveiling the neurosensory toxicity of Hg in fish has a major motivation of protecting ichtyopopulations and ecosystems, but can also provide fundamental knowledge to the field of human neurodevelopment.
汞（Hg）化合物的神经毒性和感觉毒性在人类/哺乳动物中已得到广泛研究，主要关注公共卫生问题，而鱼类方面的研究则较少且分散在不同的物种中。哺乳动物的既定前提一直在指导鱼类研究，但一些相互矛盾的发现表明，这些动物群体之间的知识转化需要谨慎[例如，甲基汞（MeHg）相对于无机汞（iHg）的相对更高神经毒性]。不同群体之间的生化/生理差异（例如鱼类大脑再生能力较高）可能决定了不同的模式。本综述旨在确定鱼类中敏感的细胞靶标和 Hg 驱动的生化/生理脆弱性，同时区分 Hg 形态的特异性。
构想了一个功能神经解剖学视角，包括：（i）Hg 在水生环境中的存在；（ii）对中枢神经系统（CNS）/感觉器官的毒代动力学；（iii）对神经传递的影响；（iv）对 CNS/感觉器官的生化/生理影响；（v）对 CNS/感觉器官的形态结构变化；（vi）行为影响。还分析了文献，以生成一个多维概念化，转化为魔方，其中提出了关键因素/过程。
Hg 的神经感觉毒性得到了明确证实。确定了与哺乳动物描述的毒性机制（主要在生化水平上）的一些对应关系。尽管研究分散在许多鱼类物种中，但确定了 29 个关键因素/过程。
确定了未来的趋势，并转化为 25 个需要解决的因素/过程。揭示鱼类中 Hg 的神经感觉毒性具有保护鱼类种群和生态系统的主要动机，但也可以为人类神经发育领域提供基础知识。
