Anxiolytic effects of buspirone and gepirone in the fear-potentiated startle paradigm.
Fear potentiation of the acoustic startle reflex was produced by eliciting startle responses in the presence of a light that had been previously paired with a shock. Buspirone (0.6-5.0 mg/kg) and gepirone (1.25-10.0 mg/kg), but not their common metabolite, 1-PP (0.5-40 mg/kg), produced a dose-dependent reduction of fear-potentiated startle. These doses of buspirone and gepirone slightly increased baseline startle levels. Reduction of fear-potentiated startle appears to involve supraspinal sites of action, since intraventricular but not intrathecal administration of buspirone (200 micrograms) reduced fear-enhanced startle. Both buspirone and gepirone were highly efficacious in this model compared to other animal tests that are used to study anxiolytic compounds.
D000818:Animals; D014151:Anti-Anxiety Agents / Q000008:administration & dosage / Q000494:pharmacology*; D002065:Buspirone / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005239:Fear / Q000187:drug effects; D007276:Injections, Intraventricular; D007278:Injections, Spinal; D008297:Male; D011743:Pyrimidines / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013216:Reflex, Startle / Q000187:drug effects*
D014151:Anti-Anxiety Agents; D011743:Pyrimidines; C039979:gepirone; D002065:Buspirone