• Antidepressant;
  • anxiolytic;
  • ultrasonic vocalization;
  • locomotion;
  • negative geotaxis;
  • rat pups
  • This study compared the effects of flibanserin, a novel 5-HT1A agonist/5-HT2A antagonist; diazepam, a traditional anxiolytic; and imipramine, a traditional antidepressant, on separation-induced ultrasonic vocalizations (USVs), locomotor behaviour, negative geotaxis and body temperature of 7–8-day-old rat pups.

  • Flibanserin (5, 10, 25 and 50 mg kg−1 s.c.) reduced USVs but had no effects on locomotor behaviour or negative geotaxis. Lower doses of flibanserin (0.5, 1, 2 and 4 mg kg−1 s.c.) had no effect on any behaviour. Diazepam (0.25, 0.5, 1 and 2 mg kg−1 s.c.) not only reduced the USVs but also increased rolling and increased the latency of the negative geotaxic response. Imipramine (10, 15, 20 and 30 mg kg−1 s.c.) reduced USVs, increased total locomotor activity and rolling but had no effect on negative geotaxis. None of the drugs altered body temperature.

  • Our data showed that flibanserin is as effective in reducing the USVs as diazepam and imipramine but has a lower incidence of motor side effects. This suggests that flibanserin might be effective for the treatment of mood disturbances such as anxiety.

British Journal of Pharmacology (2000) 130, 739–746; doi:10.1038/sj.bjp.0703364