Memory effects of the new derivative of the p-chlorophenoxyacetic acid adafenoxate compared to the effects of some cognition-enhancing drugs in rats.

In experiments on male rats the effects of adafenoxate (Adf), meclofenoxate (Mf), piracetam (Pc) and citicholine (CCh) on learning and memory were studied using the maze active avoidance method with punishment reinforcement. The drugs tested were administered twice daily for seven days at doses of 10 and 50 mg/kg body weight for Adf, Mf and CCh and only at a dose of 50 mg/kg body weight for Pc. The effects of these drugs on scopolamine-treated and scopolamine-untreated rats were also studied using the step-through method. Retention tests were given 24 h and 7 days after the end of the training session in the punishment-reinforcement active avoidance and 3 and 24 h after training in the passive avoidance situation. With the maze method statistically significant results about the favourable effects of the four drugs were obtained by most of the indices for learning and memory. However, the effects of the drugs tested were differently pronounced depending on the dose utilized. With the step-through method all four drugs prevented the scopolamine-induced amnesia. Comparing the present results with other data previously obtained about the effects of the drugs tested and of other nootropic drugs on brain biogenic monoamines, it is suggested that induced changes in biogenic monoamines are responsible for the similarities and the differences in the effects of nootropic drugs on learning and memory.