Maternal buspirone protects against the adverse effects of in utero stress on emotional and pain-related behaviors in offspring

Previous investigations from our laboratory demonstrated that prenatal stress exacerbates inflammatory pain-related behavior in adult rats and that fetal serotonin (5-HT) is involved in this phenomenon. In the present study we test the hypothesis that injections of buspirone, a 5-HT1A agonist, to rat dams before restraint stress during the last week of pregnancy (between pregnant days 15 and 20) can improve the characteristics of emotional and inflammatory pain-related behaviors in the adult offspring. Buspirone was injected to dams between the 9 and 20 days of pregnancy, during restraint stress, five min before it. The depression-like behavior in the forced swim test, formalininduced pain and body weight were investigated in the adult offspring. Prenatal stress exacerbated the licking behavior, the index of formalin-induced pain, and increased the time of immobility, the index of depression-like behavior. Buspirone normalized the licking behavior and profoundly reduced the time of immobility, which indicates differences in the mechanisms of antinociceptive and antidepressant effects of buspirone. The present new findings demonstrate that adverse influences of prenatal stress on emotional and inflammatory pain-related behaviors can be prevented by using prenatal buspirone, which shows long-term anxiolytic, antidepressant and antinociceptive effects. The new fact of body weight decrease in buspirone+stress males is worth noting in the context of the important problem of body weight gain as a common side effect of treatment with antidepressant drugs. (C) 2010 Elsevier Inc. All rights reserved.