Effects of parachlorophenylalanine on ethanol self-selection in the rat.

The efficacy of p-chlorophenylalanine (PCPA) in producing conditioned taste aversions and unconditioned avoidance of ethanol was investigated in two experiments. It was found that administering PCPA to rats having free access to a saccharine solution and water produced robust aversions to saccharin that extinguished within 6 days after termination of the PCPA treatments, thereby indicating that PCPA can produce conditioned aversions to substances consumed during its administration. In a second experiment, intraperitoneal injections of PCPA and/or ethanol given to rats not having access to ethanol were found to produce no change in their subsequent ethanol preferences. The results support the contention of earlier investigators that the reported of PCPA on the rat's preference for ethanol may have been due largely to the animals acquiring conditioned aversions to ethanol during PCPA treatments.