Methaqualone discrimination in gerbils: interactions with bemegride and imidazoline (DH-524).

Gerbils were trained in a T-maze to discriminate methaqualone (MTQ), either 16 mg/kg, 12 mg/kg, 8 mg/kg, or 4 mg/kg, from the no drug condition. Discrimination was proportional to dose, MTQ 16 mg/kg vs. no drug being the most rapidly discriminable condition. Challenge of MTQ discrimination with bemegride and imidazoline showed that bemegride, but not imidazoline reversed the MTQ discrimination. The median effective dose of bemegride was related to the amount of MTQ used (16-8 mg/kg).