COCAINE AND CAFFEINE - CONDITIONED PLACE PREFERENCE, LOCOMOTOR-ACTIVITY, AND ADDITIVITY

Conditioned place preference (CPP) was employed to clarify the reinfor cing and locomotor stimulating effects of several doses of cocaine and caffeine (0.32, 1.0, 3.2, 5.6, and 10.0 mg/kg) and to explore the pos sibility of additive effects between the two drugs. Additionally, the hypothesis that the reinforcing effects of psychostimulants are mediat ed by the same systems that control psychostimulant-induced locomotor activity was examined by conducting correlational studies between drug -induced locomotor activity and time spent in the drug-conditioned com partments. Several doses of cocaine (1.0, 3.0, 5.6, 10.0 mg/kg), and c affeine (0.32, 1.0, 3.2, 5.6, 10.0) were found to condition place pref erence and stimulate locomotor activity. A combination of low doses (0 .32 mg/kg) of each drug appeared to be additive. A positive relationsh ip between locomotor activity observed during conditioning and time sp ent in the conditioned compartment during testing was found for cocain e but not caffeine or the low-dose combination of cocaine and caffeine . (C) 1998 Elsevier Science Inc.