INVOLVEMENT OF THE DORSAL HIPPOCAMPUS IN MEDIATION OF THE ANTIANXIETY ACTION OF TANDOSPIRONE, A 5-HYDROXYTRYPTAMINE1A AGONISTIC ANXIOLYTIC

The effect of tandospirone, a 5-hydroxytryptamine (5-HT)1A agonist/anxiolytic, injected directly into dorsal hippocampus, on Vogel-type conflict behavior in rats was investigated and the findings were compared with the effects of diazepam and zopiclone. Tandospirone (30-mu-g/2-mu-l and 60-mu-g/2-mu-l) and diazepam (40-mu-g/2-mu-l) but not zopiclone (20-mu-g/2-mu-l), produced a potent anticonflict action in rats. The anticonflict action of tandospirone (30-mu-g/2-mu-l), injected into the dorsal hippocampus, was significantly blocked by (-)-propranolol (5 mg/kg i.p.). The present findings provide evidence that suggests that tandospirone has an antianxiety action, presumably by stimulating 5-HT1A receptors in the dorsal hippocampus.