Effects on open-field behavior of diazepam and buspirone alone and in combination with chronic caffeine

Effects of diazepam (1, 2 mg/kg) and buspirone (1.25, 2.5 mg/kg) on locomotor and rearing activity were observed in rats tested in an open field. Both doses of each drug reduced ambulation. However, for buspirone, this effect was confined to females. Walking and rearing was reduced by the higher dose of diazepam and rearing by both doses of buspirone. In rats that had ingested approximately 26 mg/kg/day of chronic caffeine for seven days prior to and immediately before testing, all effects of diazepam observed earlier failed to achieve significance except for ambulation. However, all earlier buspirone effects (including female-only decreased ambulation) were unaffected by the caffeine treatment. It was concluded that buspirone may be preferable to diazepam as an anxiolytic when in the presence of regular caffeine ingestion.