Fig. 7.

Effects of M100907 pretreatment on cue reinstatement of sucrose-seeking behavior (n=10), expressed as mean responses/hour ± SEM on the active lever. Animals were tested on 1 day with 1.5 μg/side M100907 (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 obtained during the extinction sessions immediately preceding each test. There was a significant increase in responding on both the vehicle and M100907 test days relative to extinction baseline. The star (★) represents a significant difference from extinction baseline, test of simple main effects, P<0.05