A multidimensional concept for mercury neuronal and sensory toxicity in fish - From toxicokinetics and biochemistry to morphometry and behavior

• Published in: Biochimica et biophysica acta. General subjects Vol. 1863; no. 12; p. 129298
• Main Authors: Pereira, Patrícia, Korbas, Malgorzata, Pereira, Vitória, Cappello, Tiziana, Maisano, Maria, Canário, João, Almeida, Armando, Pacheco, Mário
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.12.2019
• Subjects: Animals; aquatic environment; Aquatic toxicology; Behavior, Animal - drug effects; Brain; ecosystems; Fish; Fish Diseases - chemically induced; Fish Diseases - metabolism; Fish Diseases - pathology; Fishes - embryology; Fishes - metabolism; Humans; Mercury; Mercury - pharmacokinetics; Mercury - toxicity; methylmercury compounds; Methylmercury Compounds - pharmacokinetics; Methylmercury Compounds - toxicity; morphometry; motivation; neurodevelopment; Neurogenesis - drug effects; neurons; Neurotoxicity; pharmacokinetics; public health; Sensation Disorders - chemically induced; Sensation Disorders - metabolism; Sensation Disorders - pathology; Sensation Disorders - veterinary; sense organs; Sensory organs; Toxicokinetics; Sensory organs; Brain; Fish; Neurotoxicity; Mercury; Aquatic toxicology
• ISSN: 0304-4165; 1872-8006; 1872-8006
• DOI: 10.1016/j.bbagen.2019.01.020

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. [Display omitted] •Neurological disruptions of iHg and oHg were unequivocally demonstrated in fish.•A hexa-dimensional conceptualization of neuronal/sensorial toxicity was conceived.•29 key factors/processes driving the Hg neuronal/sensorial toxicity were recognized.•Futures trends were identified and translated into 25 key factors/processes.•Knowledge translation of the mechanisms from mammals to fish needs prudence.