[Evaluation of exploratory activity and anxiety in rats with different levels of impulsive behavior]

Rats were divided into 3 groups according to their preference for reinforcements of different values. Animals that preferred valuable but delayed reinforcement in more than 70% of cases formed as self-controlled group, less than 30% of cases formed an impulsive group, the rest formed an ambivalent group. Behavior of animals of different groups was scored for exploratory activity and anxiety in x-maze, fear-conditioning and novelty suppressed feeding. The least active and the most anxious in all procedures used were self-controlled rats. Ambivalent animals as compared to self-controlled and impulsive rats were the least anxious in x-maze and had more successful trials in novelty suppressed feeding test. Impulsive animals demonstrated greater percent of freezing response during acquisition of conditioned fear and they were quicker in finding food in novel environment.