title: Copper at low levels impairs memory of adult zebrafish (Danio rerio) and affects swimming performance of larvae.
abstract: Metal contamination at low levels is an important issue because it usually produces health and environmental effects, either positive or deleterious. Contamination of surface waters with copper (Cu) is a worldwide event, usually originated by mining, agricultural, industrial, commercial, and residential activities. Water quality criteria for Cu are variable among countries but allowed limits are generally in the μg/L range, which can disrupt several functions in the early life-stages of fish species. Behavioral and biochemical alterations after Cu exposure have also been described at concentrations close to the allowed limits. Aiming to search for the effects of Cu in the range of the allowed limits, larvae and adult zebrafish (Danio rerio) were exposed to different concentrations of dissolved Cu (nominally: 0, 5, 9, 20 and 60μg/L; measured: 0.4, 5.7, 7.2 16.6 and 42.3μg/L, respectively) for 96h. Larvae swimming and body length, and adult behavior and biochemical biomarkers (activity of glutathione-related enzymes in gills, muscle, and brain) were assessed after Cu exposure. Several effects were observed in fish exposed to 9μg/L nominal Cu, including increased larvae swimming distance and velocity, abolishment of adult inhibitory avoidance memory, and decreased glutathione S-transferase (GST) activity in gills of adult fish. At the highest Cu concentration tested (nominally: 60μg/L), body length of larvae, spatial memory of adults, and gill GST activity were decreased. Social behavior (aggressiveness and conspecific interaction), and glutathione reductase (GR) activity were not affected in adult zebrafish. Exposure to Cu, at concentrations close to the water quality criteria for this metal in fresh water, was able to alter larvae swimming performance and to induce detrimental effects on the behavior of adult zebrafish, thus indicating the need for further studies to reevaluate the currently allowed limits for Cu in fresh water.
authors.affiliation: Department of Biochemistry, Federal University of Santa Catarina, Florianopolis, 88040-900, Florianopolis, SC, Brazil.
authors.forename: Daiane da Silva
authors.initials: DDS
authors.lastname: Acosta
authors.affiliation: Department of Biochemistry, Federal University of Santa Catarina, Florianopolis, 88040-900, Florianopolis, SC, Brazil.
authors.forename: Naissa Maria
authors.initials: NM
authors.lastname: Danielle
authors.affiliation: Department of Molecular and Cellular Biology, Pontifical Catholic University of Rio Grande do Sul, 90610-900 Porto Alegre, RS, Brazil.
authors.forename: Stefani
authors.initials: S
authors.lastname: Altenhofen
authors.affiliation: Department of Molecular and Cellular Biology, Pontifical Catholic University of Rio Grande do Sul, 90610-900 Porto Alegre, RS, Brazil.
authors.forename: Milene Dornelles
authors.initials: MD
authors.lastname: Luzardo
authors.affiliation: Institute of Biological Sciences, Federal University of Rio Grande, 96203-900 Rio Grande, RS, Brazil.
authors.forename: Patrícia Gomes
authors.initials: PG
authors.lastname: Costa
authors.affiliation: Institute of Biological Sciences, Federal University of Rio Grande, 96203-900 Rio Grande, RS, Brazil.
authors.forename: Adalto
authors.initials: A
authors.lastname: Bianchini
authors.affiliation: Department of Molecular and Cellular Biology, Pontifical Catholic University of Rio Grande do Sul, 90610-900 Porto Alegre, RS, Brazil.
authors.forename: Carla Denise
authors.initials: CD
authors.lastname: Bonan
authors.affiliation: Department of Molecular and Cellular Biology, Pontifical Catholic University of Rio Grande do Sul, 90610-900 Porto Alegre, RS, Brazil.
authors.forename: Rosane Souza
authors.initials: RS
authors.lastname: da Silva
authors.affiliation: Department of Biochemistry, Federal University of Santa Catarina, Florianopolis, 88040-900, Florianopolis, SC, Brazil. Electronic address: alcir.dafre@ufsc.br.
authors.forename: Alcir Luiz
authors.initials: AL
authors.lastname: Dafre
mesh_terms: D000367:Age Factors; D000374:Aggression / Q000187:drug effects; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D015415:Biomarkers / Q000378:metabolism; D003300:Copper / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D005260:Female; D007814:Larva / Q000187:drug effects / Q000254:growth & development; D008297:Male; D018782:Maze Learning / Q000187:drug effects*; D009043:Motor Activity / Q000187:drug effects; D012919:Social Behavior; D065852:Spatial Memory / Q000187:drug effects*; D013550:Swimming; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D015027:Zebrafish / Q000254:growth & development / Q000378:metabolism
chemical_list: D015415:Biomarkers; D014874:Water Pollutants, Chemical; D003300:Copper; C029892:cupric chloride
keywords: behavior; copper; inhibitory avoidance; memory; toxicology; zebrafish