Fig. 4. Prior 5-HT_1B receptor antagonism in NAc potentiates subsequent cocaine and social preference.

A Cartoon showing implantation of fluid cannula for infusion of 5-HTR antagonists into the NAc of WT mice. (Inset) image showing dye injection (arrow) and damage from cannula confirming placement in medial NAc. Scale bar = 200 µm. B Schematic of cocaine CPP procedure showing pretreatment with NAc infusions of 5-HT_1B antagonist (GR 127935) at time points 75 or 135 min prior to cocaine conditioning. C Cocaine place preference scores (postconditioning-preconditioning preference) for mice following infusions of 5-HT_1B antagonist GR 127935, 5-HT₄ antagonist GR 125487, or ACSF in the NAc at time points 135 min, 75, or 135 + 75 min prior to cocaine conditioning (as depicted in B) (n = 4–13). D Schematic showing pretreatment NAc infusion of 5-HT_1B antagonist prior to three-chamber social interaction assay. E Representative heatmaps indicating the distribution of time spent in the social interaction apparatus after infusion of GR 127935 into the NAc 135 min prior and ACSF infusion control. F Social interaction ratio (time spent in social zone/time spent in empty zone) following pretreatment with GR 127935 (n = 10–11).