Figure 8.

Cocaine-induced conditioned place preference. Conditioning was performed as described in Figure 7A with cocaine (10 mg/kg, i.p.). Data are shown as the difference in the time spent in the drug-paired compartment on the postconditioning day and the preconditioning day when the preconditioning and postconditioning times were set at 10, 15, or 20 min (mean ± SEM). Cocaine (10 mg/kg, i.p.) produced preference for the cocaine-paired compartment in both genotypes that did not differ under any of the conditions (for genotype, F_(1,16) = 0.05, p = 0.8179; for time, F_(2,32) = 5.95, p < 0.01; n = 9-10 per group).