Resumo

Objective – Stress involves a group of reactions and stimulus that are capable to promove several changes on the organism including harmful effects in the cognitions functions mainly in learning and memory. On the other hand, anxiolytics like benzodiazepinics promoves alterations on HPA axis reducing the agents’ stressors effects. The aim of the present study is to investigate the effects of diazepam acute administration in males mice that underwent to acute restraint stress in the plus-maze discriminative avoidance task for concomitant evaluation of learning, memory, anxiety levels and locomotor activity. Methods – Male Swiss mice (35 - 40g) were allocated to the following groups: Saline-Control (SC), Diazepam-Control (DzpC), Saline-Stress (SS) and Diazepam-Stress (DzpS). The animals of the experimental groups were placed in cylindrical restraint tubes (30 min) meanwhile the controls groups were handling. One hour later, diazepam (2 mg/kg) or saline was administrated i.p. 30 min before trainning session. Each animal was placed in the center of the plus maze with two open arms and two closed arms. In one of the closed arms, aversive stimuli (light and noise) were presented every time the animal entered in the aversive arm (training session) after 24 h mice were placed again in plus maze but without stimuli (test session). The duration that each animal spent in each arm were registered throughout 10 minutes in each session. Results – Our results showed that the animals administrated with diazepam demonstrated deficit of evocation of memory (Test: SC = 34,2 ± 0,7; DzpC = 67,3 ± 3,4;). Even as the animals stressed that also when administrated with diazepam demonstrated deficit (Test: SS = 56,4 ± 15,3; DzpS = 81,6 ± 3,6). As expected the animals under effect of diazepam explores more the open arms (SC = 3,3 ± 1,4; DzpC = 20,2 ± 7,2; SS = 7,6 ± 1,7; DzpS = 27,2 ± 15,3). Conclusion – The benzodiazepinic diazepam presented your anxiolytic effect that is possible related with the deficit on memory. This deficit can be potentiated in animals submitted to restraint stress, but more studies are needed to ensure that these differences. Financial Support – CNPq e PROPESQ/UFRN