[Administration of quinpirole with 17beta-estradiol in low doses corrects active avoidance performance in...

The influence of D1/D2 types of dopaminergic receptors on the dynamics of acquisition and extinction of active avoidance performance and the behavior of ovariectomized female rats has been studied in the open field test. The DI-type dopaminergic receptor agonist SKF-38393 (0.1 mg/kg, i.p.) and D2-type dopaminergic receptor agonist quinperole (0.1 mg/kg, i.p.) were administered chronically (14 days) alone or in combination with low dose of 17beta-estradiol (0.5 microg/rat, s.c.) in animals after ovariectomy. It is established that quinperole in combination with low dose of 17beta-estradiol completely corrected impairments in the mechanisms of formation and retention of active avoidance performance in ovariectomized females. After quinperole treatment, this effect was also accompanied by the correction of behavior in the open field test. In contrast, the administration of SKF-38393 alone or in combination with low dose of 17beta-estradiol in female rats with estrogen deficiency neither corrected the formation and reproduction of active avoidance response of animals nor modified their behavior in the open field test. The results of the present study suggest important role of D2-type dopaminergic receptors in active avoidance performance development in animals with estrogen deficiency.