Control site microinjections are ineffective. VTA microinjection placements (left): microinjection sites for animals with bilateral VTA cannulae (black dots) are represented. Control site injections (right): microinjection sites outside the borders of the VTA are represented, from animals with unilateral (yellow/light gray dots) or bilateral (green/dark gray dots) cannula placements in nearby structures. For VTA and control site animals, bilateral placements were collapsed into a unilateral view for presentation [adapted from Paxinos and Watson (2007)]. Control site microinjections ineffective: cue-triggered reinstatement data for animals with unilateral or bilateral cannula placements outside the VTA are shown, after microinjections of vehicle (Veh), SB-334867 (SB; 1 mM), CNQX/AP-5 (0.7/1.6 mM), or contralateral SB and CNQX/AP-5 (Contra). Inactive lever presses are shown with black bars