Avaliação dos efeitos promovidos pelo estresse agudo e estresse crônico imprevisível sobre o padrão do comportamento exploratório em peixe-zebra

• Ano de defesa: 2023
• Autor(a) principal: Borba, João Vitor de
• Orientador(a): Rosemberg, Denis Broock
• Banca de defesa: Franco, Jeferson Luis, Dalmaz, Carla
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Santa Maria; Centro de Ciências Naturais e Exatas
• Programa de Pós-Graduação: Programa de Pós-Graduação em Ciências Biológicas: Bioquímica Toxicológica
• Departamento: Bioquímica
• País: Brasil
• Palavras-chave em Português: Estresse; Campo aberto; Comportamento exploratório; Zonas-base; Peixezebra
• Palavras-chave em Inglês: Stress; Open field; Exploratory behavior; Homebase; Zebrafish
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::BIOQUIMICA
• Link de acesso: http://repositorio.ufsm.br/handle/1/28334

Stress is a set of biological reactions that allow the body to adapt itself to physiological disturbances generally evoked by some external stimulus. Currently, the term is popularly associated with exacerbated levels of stress, leading to physical and mental damage, which affect a large part of global population. Configurated as a human health problem, stress is an important topic in research using different animal models in order to better understand its underlying physiological and neurobehavioral mechanisms. In this perspective, zebrafish (Danio rerio) represents a relevant organism for the investigation of the effects generated by different types of stress due to its well-characterized behavioral repertoire and biological pathways that resemble those of humans, for example. Thus, the present study aimed to investigate the effects generated by acute and unpredictable chronic stress on the spatiotemporal organization of exploration in zebrafish submitted to the open field test. For this, adult fish of both sexes were subjected to acute stress (AS) from exposure to 1L of dechlorinated water in absence (control group) or presence of conspecific alarm substance (CAS - AS group) at 3.5 mL/L for 5 minutes. Chronic unpredictable stress protocol (UCS) was performed during 7 consecutive days, in which different stressors were applied two times daily in an unpredictable manner. After CAS exposure and on the eighth day, in the case of the UCS group, the animals were individually positioned in the center of circular arenas with dimensions 25 x 6 cm (diameter x water column height). The behavior was recorded for 30 minutes by a camera positioned at the top of the apparatus and later analyzed to identify the homebases and quantify its related parameters. In general, after the first 15 minutes of trial, AS group used the homebase to perform brief trips to the center and periphery of the arena. Conversely, UCS behavioral profile was characterized by high levels of immobility, “burst swimming” and peripheral excursions. Curiously, differently of UCS, the acute stress did not generate an increase in thigmotaxis in comparison to control. In general, our results show that the sequential organization of exploratory behavior in zebrafish is sensible to the modulation of different stress protocols, reinforcing the utility of homebase-related behaviors for the analysis of distinct affective-like states.