Figure 4.

Effect of infusion of two doses of the D₁-D₂ dopamine receptor antagonist α-flupenthixol (top panel; n = 5) or the AMPA-KA antagonist LY293558 (bottom panel; n = 6; also used in disconnection study) into the NAcc core on the mean ± SEM number of responses on the active lever (dark bars) and inactive lever (open bars) for cocaine under a second-order schedule of cocaine reinforcement. Responses before self-administered cocaine during the first interval and after self-administered cocaine are given in the left and right panels. The asterisk denotes difference from vehicle (Veh) during that interval (n = 11).