Efeito do comportamento do gato nas respostas defensivas e nociceptivas de ratos

• Autor(a) principal: Magalhães, Marcus Vinícius Ferreira
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFS
• Texto Completo: https://ri.ufs.br/handle/riufs/4000
• topic: Fisiologia; Analgesia; Dor; Ansiedade; Medo; Respostas defensivas; Defensive behavior; Pain; Fear; Anxiety; CIENCIAS BIOLOGICAS::FISIOLOGIA

Defensive responses vary according to the distance between prey and predator and the degree of threat that every situation offers. Studies suggest that the confrontation with the predator produces different types of analgesia as well as, the occurrence of anxiety and fear. The evaluate the effect of exposure of rat to different aversive conditions in defensive and nociceptive responses was our pursue. Therefore, we used 48 Wistar male rats weighing 250 to 350 g. On day 1, defensive and nociceptive responses of CTRL (without the cat's presence), GAt (active cat) and GIn (inactive cat) groups was evaluated. It was N = 16 animals per group, divided into groups with or without the possibility of escape to the shelter in the behavioral test arena (5 min), followed by hot plate test to measure the nociceptive response of rats. The following day (Day 2), all animals were returned to behavioral testing arena, for 5 min, to re-exposure to aversive environment (without the presence cat). GAt (p <0.01) and GIn (p = 0.03) groups had a significantly higher freezing time than CTRL. Additionally, GAt and GIn groups presented, respectively, shorter rearing (p <0.01; p = 0.02) and fewer quadrants crossing (p <0.01; p = 0.01). Farther, GAt group exhibited antinociceptive response at time 0, which was significantly different from baseline (p <0.01) and interval time 60 (p = 0.01). Still on day 2, GAt group had significantly higher freezing than GIn group (p= 0.04), additionally, the animals of GIn group, without the possibility of escape to the shelter, had higher rearing duration (p = 0.01) and number of quadrants intersections than CTRL and GAt groups without the possibility of escape to the shelter (p = 0.02; p < 0.02). GIn group showed a higher number of risk assessment than CTRL (p = 0.01). On day 2, no group showed significant antinociceptive response. The results suggest that cat's behavior has a direct influence on behavioral and nociceptive response of rats. In this sense, the presence of an active cat promoted the increase in freezing duration, the decrease exploratory activity and it induced antinociception responses in rats, besides promoting freezing responses in them after a re-exposure to aversive context.