Adolescent and adult mice display differential sensitivity to the effects of bupropion on the acquisition of a water maze task.

Background: Adolescence is characterized by major neurobiological changes, and the effects of some psychoactive drugs seem to differ between adolescents and adults. Bupropion, an antidepressant that is also used to treat nicotine addiction, induces behavioral actions in both adolescent and adult rodents. However, the effects of this drug on spatial ability have not been compared in animals at different stages of their development. The present study was conducted to assess the effects of bupropion on spatial learning and memory in adolescent and adult mice.

Methods: Adolescent (post-natal day: PND35-36) and adult (PND >65) NMRI mice received bupropion (10, 20 and 40mg/kg) or saline during the acquisition (4 trials/day on 5 consecutive days) of a Morris water maze (MWM) task. Retention was evaluated with a probe trial performed after the acquisition phase.

Results: Data showed that age did not affect performance of the task. However, the factor Drug treatment reached statistical significance, with high doses of bupropion (40 and 20mg/kg) impairing acquisition of the MWM test in adolescents. The drug did not induce detrimental effects on the acquisition or retention of the task in adults.

Conclusion: Bupropion impairs acquisition of the spatial task in adolescent but not in adult mice. It does not seem to alter retrieval of previously acquired spatial information in either adolescents or adults. Our findings suggest that, during the adolescent period, mice are more vulnerable to the actions of bupropion on spatial learning.