Activation of the BNST–vSUB pathway reduces context fear expression but not cued fear expression. (A) Schematic of the behavioral protocol. (B) Percentage freezing in response to the CS+ tone during training (±SEM). (C) Percentage freezing during each of the 10 min of context fear expression (±SEM). Animals received infusions of the hM3D(Gq) agonist J60 or saline 30 min prior to testing. Animals with both CRE and hM3D(Gq) viral infusions and J60 injection froze significantly less than the other two groups. (D) Percentage freezing averaged over the 10 min of context fear expression. The asterisk denotes a significant difference between groups (P < 0.05). (E,F) Percentage freezing (±SEM) to 10 CS+ tones (E) and 10 CS− tones (F) during the tone test. Animals received infusions of J60 or saline 30 min prior to testing. (G,H) Percentage freezing in response to 10 CS+ tones (G) and 10 CS− tones (H) 24 h after cued fear expression, testing extinction recall. Animals were tested drug-free for extinction recall.
