Effect of BMY 21502 on acquisition of shape discrimination and memory retention in monkey.

BMY 21502 is a novel pyrrolidinone nootropic with demonstrated ability to reverse electroconvulsively induced amnesia in rodents. We administered BMY 21502 intramuscularly to four monkeys (Macaca radiata) during testing using two separate paradigms. The first test involved the acquisition of a visual shape discrimination task where each monkey learned to select the correct lighted panel. In the second task, memory retention was tested by having the monkeys select and press the correct lighted panel using a delayed matching-to-sample procedure. A dose-response relationship was established for the acquisition of shape discrimination for each monkey. Two performance-enhancing doses in the visual discrimination task were then employed to test for effects on memory retention at different delay intervals in the delayed-matching-to-sample task. Results indicate that BMY 21502, when administered over a wide dose range, enhanced acquisition of shape discrimination in three of four monkeys when combined drug scores were compared to vehicle-only scores (p less than 0.02). However, BMY 21502 produced no significant improvement in memory retention at any of seven different delay intervals when low-dose and high-dose scores for the three responding monkeys were compared to vehicle-only scores.