Behavioral and neurotoxic effects of arsenic exposure in zebrafish (Danio rerio, Teleostei: Cyprinidae).
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.
de Castro
Micheli Rosa
MR
Programa de Pós-graduação em Ciências Fisiológicas, Fisiologia Animal Comparada, Universidade Federal do Rio Grande (FURG), Rio Grande, RS, Brazil.
Lima
Juliane Ventura
JV
de Freitas
Diana Paula Salomão
DP
Valente
Roberto de Souza
Rde S
Dummer
Natália Seus
NS
de Aguiar
Rosiane Borba
RB
dos Santos
Luciane Cougo
LC
Marins
Luis Fernando
LF
Geracitano
Laura Alicia
LA
Monserrat
José María
JM
Barros
Daniela Martí
DM
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
D008464:Mecamylamine; D009538:Nicotine; D001151:Arsenic