Pharmacological inactivation of vmPFC following 0 and 2 extinction sessions. A, Experimental timeline for the inactivation experiment. We trained rats to self-administer food for 7 d and then divided them into 2 groups that underwent 0 or 2 extinction sessions. On test day, we bilaterally injected vehicle or the GABA-A and GABA-B agonists muscimol+baclofen into the vmPFC 10 min before a 15 min test session under extinction conditions. B, Active lever presses, pellets earned, and inactive lever presses over 7 d of food self-administration and extinction training. Data are mean ± SEM. C, Figure showing placement of cannulas. D, Mean ± SEM number of active lever presses on the last day of self-administration indicates no differences before testing. E, Mean ± SEM number of active lever presses over a 15 min test following vehicle or muscimol+baclofen injections. (n = 6 per group).