The anxiogenic action of Ro 5-4864 is reversed by phenytoin

Ro 5-4864, a selective ligand for the benzodiazepine micromolar and peripheral receptors, had a significant dose-related (5-20 mg/kg) anxiogenic action in the social interaction test of anxiety. This anxiogenic effect was reversed by phenytoin (10 mg/kg), a ligand for the micromolar receptors, but unaffected by the isoquinoline PK 11195 (10 mg/kg), a ligand for the peripheral receptors.