Effects of acute intra-hippocompal injection of bupropion on active avoidance learning in rats

Introduction: Learning and memory deficits in some diseases are new subjects of research. Bupropion, as dopamine and noradrenaline reuptake inhibitor and an antidepressant agent, has been previously shown to affect learning and memory processes. This study was designed to test the effect of intra-hippocompal bupropion injection on active avoidance learning task in rats. Methods: Adult male Wistar rats (obtained from Pasteur Institute of Iran, weighing 200-250 g) were tested for learning behavior in a two-way active avoidance shuttle-box. The animals were divided into control, sham operated, vehicle and 3 treatment groups treated with different doses of intra-hippocampal bupropion (0.25 mg/1 μL, 1.25 mg/5 μL and 2.5 mg/10 μL, injected during 1-2, 5 and 10 min, respectively). Drug was injected by a stereotaxic implanted guide cannulae. Briefly, 10 days after the stereotaxic surgery, rats were trained (20 trails, 2 times each day) in a twoway active avoidance task shuttle box. Sessions were started at the same time of the day and an interval of 5 hours was between the 2 sessions. Tests were repeated on 5 consecutive days. Rats received bupropion or vehicle 30 min before each test and the learning process was assessed. Results: Analysis of the data showed significant differences in the number of avoidance reactions in the early sessions of trials of the learning tasks between vehicle and bupropion treated animals (p<0.05). Conclusion: Bupropion can decrease the number of avoidance reactions and increase the reaction latency. Although bupropion is a dopamine reuptake blocker, but it is concluded that bupropion can bind to other receptors such as acetylcholine receptors and interfere with the learning and memory processes. Key words: Bupropion, Shuttle-box, Active avoidance learning, Hippocampus, Antidepressant