LOCOMOTOR AND ANTIDEPRESSANT-LIKE EFFECTS OF 5-HT(1A) AGONIST LY-228729 IN PRENATALLY BENZODIAZEPINE-EXPOSED RATS

Locomotor activity and antidepressant-like effect in the forced swim t est (FST) of 5-HT(1A) agonist LY 228729 were investigated in adult rat s prenatally exposed at doses of diazepam (DZ) and alprazolam (ALP) wh ich induce persistent downregulation of GABA/benzodiazepine (BZ) recep tors. Prenatal exposure to ALP and DZ did not modify the efficacy of s ubchronic LY 228729 to decrease immobility time in the FST. Prenatal D Z and ALP potentiated the facilitatory effect of subchronic LY 228729 on locomotor activity; prenatal DZ was more effective than prenatal AL P. Moreover, prenatal DZ increased stereotypic movements induced by LY 228729. These data suggest that the persistent downregulation of GABA /BZ receptors, induced by prenatal BZs, does not play a role in the an ti-immobility effect in the FST of 5-HT(1A) agonist LY 228729 while it can increase locomotor activity and stereotypic movements. Moreover, this study indicates that increases in locomotor activity do not seem to influence the anti-immobility effect in the FST of LY 228729 in rat s. (C) 1998 Elsevier Science B.V./ECNP.