ACUTE PHENCYCLIDINE INDUCES AVERSION, BUT REPEATED PHENCYCLIDINE INDUCES PREFERENCE IN THE PLACE CONDITIONING TEST IN RATS

Phencyclidine (PCP) is a drug that has been widely abused in the past two decades. PCP produces place aversion, but not preference, in the p lace conditioning test. The present study examined PCP-induced place c onditioning behavior in rats treated with PCP repeatedly. In naive rat s, PCP (2-8 mg/kg i.p.) dose dependently produced place aversion, but did not produce any effect in rats treated with PCP (10 mg/kg i.p.) fo r 14 days, indicating that tolerance developed to PCP-induced place av ersion on repeated PCP treatment. In rats treated with PCP (10 mg/kg i .p.) for 28 days, PCP (2-8 mg/kg i.p.) dose dependently produced place preference. These findings suggest that some changes in neuronal func tion induced by the repeated PCP treatment may play an important role in the addiction to this drug.