Interactions of Ro 15-4513 with diazepam, sodium pentobarbital and ethanol in a holeboard test

Ro 15-4513 (1.5 mg/kg) decreased the exploratory activity of mice in a holeboard test. This effect was reversed by diazepam (1 mg/kg), ethanol (1 g/kg) and sodium pentobarbital (15 mg/kg). Higher doses of these three agents reduced the number of exploratory head-dips, and Ro 15-4513 antagonised these effects. These observations are consistent with the suggestion that Ro 15-4513 is a partial inverse agonist at benzodiazepine receptors and acts by reducing the efficacy of GABA. Ro 15-4513's interaction with ethanol in the holeboard closely resembled its interaction with the barbiturate.