Figure 3.

Effects of the AMPA/KA receptor antagonist LY293558 on self-administration of cocaine under a second-order schedule of reinforcement. Left, LY293558 infusion into the dorsal striatum decreased the number of active lever presses in the first, drug-free interval. Right, LY293558 into the dorsal striatum did not affect the number of inactive responses. Data are presented as mean ± SEM responses during the first 15 min interval of the session. *p < 0.05, different from vehicle (Student–Newman–Keuls test).