Effects of pre- and post-trial caffeine administrations upon “step-down” passive avoidance behavior in rats submitted or not to electroconvulsive shock

Abstract

Summary The influence of caffeine upon avoidance behavior in the rat was studied by administering the drug at the doses of 1, 2 and 20 mg/kg, i.p., 45 min before the acquisition of a single-trial “step-down” task and by testing the animals 24h later. In order to better detect a possible facilitating effect of caffeine, half of the animals of each group was submitted to electroconvulsive shock (ECS) immediately after training. 1 and 2 mg/kg of caffeine given 45 min before training did not influence passive avoidance conditioning of rats not submitted to ECS, whereas 20 mg/kg significantly impaired avoidance behavior. A possible state-dependent learning component for the effect of the highest dose was ruled out by treating animals 45 min before both sessions. ECS-induced amnesia was prevented by 1 mg/kg of caffeine given i.p. 45 min before training, whereas the other doses were ineffective to this regard. Post-trial administrations of 1 and 20 mg/kg of caffeine were without effect both on ECS-induced amnesia and on avoidance behavior of rats not submitted to ECS. Present findings suggest that a low dose of caffeine has a potential facilitating effect upon passive avoidance conditioning which can be revealed when memory processes are impaired by an injuring event like ECS.