title: Behavioral and neurotoxic effects of arsenic exposure in zebrafish (Danio rerio, Teleostei: Cyprinidae).
abstract: This study investigated the passive avoidance conditioning in zebrafish (Danio rerio). An instrument was developed for measuring escape responses triggered by a conditioned stimulus. This system allowed quantification of latency of crossing from a light to a dark zone. Zebrafish were trained to swim from an illuminated to a dark compartment, where they received a body shock (training session). The proposed methodology was efficient for evaluation of working, short, and long-term memory formation of an aquatic animal model. The possibility of employing memory measurements in toxicity tests, in order to obtain an ecologically meaningful biomarker response, was also analyzed. In this experiment, immediately after the training session, fish were exposed to three arsenic (As(V)) concentrations. After the test session, the brain was removed for biochemical analyses. A control group was kept in tap water. After exposure, animals were submitted to a one-trial inhibitory avoidance test for measurement of long-term memory (LTM). Results from behavioral and biochemical analyses showed that the three As(V) concentrations impaired LTM (p<0.05) and increased protein oxidation, which suggests an amnesic and pro-oxidant effect of As(V). Evaluation of behavior parameters in aquatic models is an important complement in studies concerning the environmental impact of chemical substances.
authors.affiliation: Programa de Pós-graduação em Ciências Fisiológicas, Fisiologia Animal Comparada, Universidade Federal do Rio Grande (FURG), Rio Grande, RS, Brazil.
authors.forename: Micheli Rosa
authors.initials: MR
authors.lastname: de Castro
authors.forename: Juliane Ventura
authors.initials: JV
authors.lastname: Lima
authors.forename: Diana Paula Salomão
authors.initials: DP
authors.lastname: de Freitas
authors.forename: Roberto de Souza
authors.initials: Rde S
authors.lastname: Valente
authors.forename: Natália Seus
authors.initials: NS
authors.lastname: Dummer
authors.forename: Rosiane Borba
authors.initials: RB
authors.lastname: de Aguiar
authors.forename: Luciane Cougo
authors.initials: LC
authors.lastname: dos Santos
authors.forename: Luis Fernando
authors.initials: LF
authors.lastname: Marins
authors.forename: Laura Alicia
authors.initials: LA
authors.lastname: Geracitano
authors.forename: José María
authors.initials: JM
authors.lastname: Monserrat
authors.forename: Daniela Martí
authors.initials: DM
authors.lastname: Barros
mesh_terms: D000818:Animals; D001151:Arsenic / Q000633:toxicity*; D001362:Avoidance Learning / Q000187:drug effects*; D001522:Behavior, Animal / Q000187:drug effects; D003214:Conditioning, Classical / Q000187:drug effects*; D008464:Mecamylamine / Q000494:pharmacology; D008568:Memory / Q000187:drug effects; D009538:Nicotine / Q000494:pharmacology; D018384:Oxidative Stress; D015027:Zebrafish
chemical_list: D008464:Mecamylamine; D009538:Nicotine; D001151:Arsenic