Pre-infusion with a BDNF scavenger, TrkB/Fc, prevented the suppressive effect of intra-PFC BDNF on cocaine-seeking during day 1 of extinction responding. V-V=vehicle-vehicle; V-B=vehicle-BDNF; Fc-V=TrkB/Fc-vehicle; Fc-B=TrkB/Fc-BDNF. Avg SA 8,9,10=average number of active lever presses on the last 3 days of cocaine self-administration; 2hr Ext Test= 2hr extinction test 22 hr after the 10th self-administration session. *p<0.05 vs. V-V; ##=p<0.005 vs. V-B; +=p<0.05 vs. Avg SA 8,9,10 within each group.