Rug. Neuidsychophard S Bid Psych&d 1998, Vol. 22, pp. 229-239 Published by Elsevier Sdcnce Inc. PrintedintheUSA. Allrightsreserved 0278~!3346/98 $0.00 + .oO PII 9027~5946(97)0010s-x ESTABLISHING ORALLY SELF-AIMMINISTERED COCAINE AS A REINFORCER IN RATS USING HOME-CAGE PRE-EXPO!3URE* J. DAVID JENTSCH’*+, PAMELA J. HENRY’, PATRICK A. MASON’, JAMES H. MERRITT3, and JOHN M. ZIRIAX’ ‘Operational Technologies Corp, San Antonio, Texas, USA; ‘Systems Research Laboratories, San Antonio, Texas, USA; ‘Radiofrequency Radiation Division, Brooks Air Force Base, Texas, USA. (Final form, October 1997) Jentsch I. David, Pamela J. Henry, Patrick A. Mason, James H. Merritt, and John M. Ziriax: Establishing Orally Self-Administered Cocaine as a Reinforcer in Rats Using Home-Cage Pm-Exposure. Prog. Neuro- Psychopharmacol. & Biol. Psychiat., 1998, a. pp. 22%X% Published by EIsevier sdence Inc. 1. Rats were force-exposed to a cocaine+saccharin solution in their home cage water bottles for five days. They were then given 5 h home-cage access to both cocaine and cocaine-free solutions for 40 days. 2. The subjects consumed large doses of the cocaine solution despite the ad zyxwvutsrqponmlkjihgfedcbaZY lib&m availability of water. 3. The animals were then trained on a task consisting of operant bar pressing rewarded on an intermittent schedule with a liquid cocaine reinforcer. 4. All subjects performed the operant task and consumed doses of cocaine soIution which are preferred over water in other paradigms. 5. Levels of responding were significantly reduced in three of four subjects when vehicle was substituted for liquid cocaine as the reward. 6. This demonstrates that orally self-administered cocaine can be used as a reinforcer in rats. Keywords: drinking, drug abuse, motivation, operant behavior, reward, self-administration. . . Abbrevlatlons: intercomponent interval (ICI), intravenous (IV), radiofrequency radiation (RFR), random ratio (RR), responses (resp). ‘Views presented are those of the authors and do not reflect the official policy or position of the US Air Force, Department of Defense, or U.S. Government. Portions of this data have been previously reported in abstract form. Jentsch JD, Ziriax JM, Henry PJ, and Mason PA. Establishing oral cocaine as a reinforcer in rats: A home cage method. Sot. Neurosci. Abstr. 211:248.7, 1994. **Present address: Section of Neurobiology, Yale University School of Medicine, New Haven, Connecticut, 065 IO, USA. 229