ESTABLISHING ORALLY SELF-ADMINISTERED COCAINE AS A REINFORCER IN RATSUSING HOME-CAGE PREEXPOSURE

1. Rats were force-exposed to a cocaine+saccharin solution in their ho me cage water bottles for five days. They were then given 5 h home-cag e access to both cocaine and cocaine-free solutions for 40 days. 2. Th e subjects consumed large doses of the cocaine solution despite the ad libitum availability of water. 3. The animals were then trained on a task consisting of operant bar pressing rewarded on an intermittent sc hedule with a liquid cocaine reinforcer. 4. All subjects performed the operant task and consumed doses of cocaine solution which are preferr ed over water in other paradigms. 5. Levels of responding were signifi cantly reduced in three of four subjects when vehicle was substituted for liquid cocaine as the reward. 6. This demonstrates that orally sel f-administered cocaine can be used as a reinforcer in rats.