Intense Sweetness Surpasses Cocaine Reward
Figure 4
Pharmacological and economic determinants of cocaine choice.
a, Cocaine-induced locomotion as a function of dose. Locomotion (i.e., mean number of cage crossings±SEM) was measured during 10 min after the first cocaine self-injection of the first day of each dose substitution. b, Choice between levers C and S (mean±SEM) as a function of dose. c, Choice between levers C and S (mean±SEM) as a function of delay between response and saccharin delivery. *, different from the shortest delay (P<0.05, Fisher's LSD test after one-way ANOVA). d, Choice between levers C and S (mean±SEM) as a function of reward price. *, different from the lowest price (P<0.05, Fisher's LSD test after one-way ANOVA). The values of each variable (dose, delay and price) were tested at least 5 times in a row until stabilization of behavior. Bars represent the means of the last 3 stable days.