The combination of alcohol and cocaine does not produce effects greater than either drug alone in a place conditioning design

Cocaine/alcohol combinations have been reported as more rewarding than either drug alone. This study extended these analyses by examining the combination within a place preference preparation. Three groups of rats were injected IP with 20 mg/kg cocaine (Group C), 0.5 g/kg alcohol (Group A) or the cocaine/alcohol combination (Group C/A) before being restricted for 30 min to a compartment in a place conditioning chamber. The following day, subjects were injected with the vehicle and restricted to the other side. This was repeated for four cycles. Following conditioning, subjects were given 15-min access to the entire chamber to assess their compartment preference. Group C displayed a significant preference for the drug-paired compartment. Group A displayed a nonsignificant aversion to the drug-paired compartment. Group C/A displayed no preference for the drug-paired compartment, suggesting that within this preparation the combination does not produce rewarding effects greater than either drug alone.