[Effect of D1/D2 dopamine receptors agonists and antagonists on rats with different choice of reinforcement value].

The effects of D1/D2 dopamine receptors agonist (SKF, TNPA) and antagonist (SCH 23390, raclopride) on rat behavior, associated with the choice of the reinforcement value were investigated. Animals were divided into two typological groups--group of impulsive, choosing low-value immediate reinforcement, and self-control group, preferring valuable delayed reinforcement (paradigm delay-discount). The results showed that i.p. administration of D1/D2 receptors antagonists (SCH 23390 and raclopride) resulted in a statistically increase in the choice of pedals with immediate reinforcement of low value in animals of self-control group, without causing a change in the behavior of impulsive rats. Also, the increase in number of missed responses was obtained. When D1/D2 receptors agonists (SKF, TNPA) were administered no significant changes were observed in rats' behavior. However, we noted a trend to change the preferences in choosing pedals for reinforcements, which was different in the rats of two groups--the self-control rats showed a decrease of pressing the pedal to get valuable delayed reinforcements, while in impulsive animals, on the contrary, the number of elections pedal receive valuable reinforcements increased. Thus our results suggest the difference between the effects of dopamine in animals differing in their individual and typological characteristics.