Effect of mPFC α-1 adrenergic blockade on extinction memory in sham and nVH lesioned animals. A, shows extinction learning curve of rats infused with either ACSF or benoxathian (Ben) bilaterally into infralimbic PFC, 30 minutes before the session (arrow sign). B, Bar diagram of mean (± SEM) freezing response at the last block of 2 trials in the four groups of animals. Sham animals with mPFC benoxathian infusion, compared to ACSF, show higher freezing indicating resistance to extinction learning. However, the α-1AR antagonist has no significant effect in nVH lesioned animals, i.e., do not exacerbate extinction deficit of lesioned animals (*p=0.002 and #p=0.004 compared to sham-ACSF group. C, Freezing responses of the animals during the extinction recall. D, Mean ± SEM of freezing response at the last block of 2 tone trials during recall (#p=0.0003 compared to sham-ACSF).