Fig. 1.

Experimental design overview. Group 1 animals (n = 21) were trained to self-administer cocaine with light+tone cues and then trained on the within-session threshold procedure with light+tone cues. These animals were then pretreated with either SB or vehicle (veh) prior to testing on the within-session threshold procedure with cues. Group 1 animals were then split into 2 subgroups and re-stabilized on the threshold procedure either with (n = 8) or without light+tone cues (n = 13). Animals were again pretreated with either SB or vehicle prior to testing on the within-session threshold procedure. All Group 1 animals were then run on extinction sessions and tested for cue-induced reinstatement with SB or vehicle pretreatment in a counterbalanced fashion. Group 2 animals were trained to self-administer cocaine without light+tone cues and then trained and tested on the within-session threshold procedure without light+tone cues.