Correction of pain-related and affective behavior by combination of fluoxetine and buspirone in prenatally stressed rats

The inhibitor of serotonin (5-HT) reuptake fluoxetine does not cause any improvement in every patient suffering from depression; moreover, fluoxetine during pregnancy disrupts the normal development of the fetus. Clinical observations in adult patients suggest that treatment of depression with a combination of fluoxetine and 5-HT1A receptor agonists has a higher therapeutic effect than the effect of a single fluoxetine. In the present study, the effect of chronic management of the combination of fluoxetine and a 5-HT1A receptor agonist anxiolytic buspirone was examined in order to correct the adverse effects of prenatal stress on pain and affective behavior in the female offspring during the prepubertal period of development. It was found that the immobilization stress of rat dams in the last third of pregnancy (the stress of rat dams during pregnancy is used as a model of human depression) caused in the offspring the increased functional activity of the pain system, an increase in the level of depressive-like behavior. Chronic administration to pregnant dams of fluoxetine, buspirone, or their combination has improved the characteristics under study in the female offspring. The results indicate that the chronic administration of a combination of fluoxetine and buspirone during the gestation of rat dams neutralized the negative effect of prenatal stress in female offspring. More effective action of the combination of the drugs compared with the action of fluoxetine was revealed in the pain sensitivity to thermal stimulus and in the first acute phase of pain behavior in the formalin test. Undesirable deviations in the investigated types of behavior in female rats subjected to pharmacological effects of each of the drugs during the prenatal period were not revealed.