Effects of meclofenoxate on learning and memory--dependence on the experimental conditions

In experiments on male albino rats, it was found that meclofenoxate at a dose of 100 mg/kg i. p. applied 7 days before and 5 days during shuttle-box training did not influence learning but significantly facilitated retention (retention test was given 7 days after the end of training). With the step-through method for passive avoidance meclofenoxate at the same dose applied for 7 days improved learning and retention. In the staircase maze training with alimentary reinforcement and in the step-down passive avoidance situation, meclofenoxate at a single dose (50 mg/kg i. p.) applied before or immediately after training only tended to facilitate learning and retention, while applied at the same dose twice daily for 5 days, it significantly improved learning and retention. When meclofenoxate at a dose of 50 mg/kg i. p. was administered twice daily for 5 days in parallel with the staircase maze training, learning reached its maximum on the 5th day and remained at this level till the 10th training day even after withdrawal of meclofenoxate. In the control animals the improvement of learning progressively increased till the 10th training day. The present results suggest that the learning- and memory-facilitating effect of meclofenoxate is influenced by the training method, motivation, dose used and treatment duration.