Fig. 4.

The effects of 1.5μg/0.2μl/side M100907 on cue-elicited reinstatement of extinguished cocaine-seeking behavior when injected directly into the Cg2 region of the anterior cingulate cortex (n=8), which served as an anatomical control site. Animals received 1.5 μg/0.2 μl/side M100907 and were tested on 1 day with their assigned dose (striped bar) and on another day with the vehicle (black bar), with order counterbalanced. These pretreatments were infused within 1 min before placing the animals into the self-administration chambers, where light and tone cues were available response-contingently on an FR1 schedule. Baselines (white bar) were calculated as the average number of active lever presses during the extinction sessions immediately preceding each test. The asterisk (*) represents a significant difference from extinction baseline, test of simple main effects, P<0.05