ADX47273 administration coupled to a single retrieval trial enhances fear extinction. (Ai) Freezing during tone-cued fear conditioning in Day 1. (Aii) Tone-cued freezing upon a single CS presentation (180 sec) on Day 2 (retrieval). (Aiii) Within-session fear extinction after the single retrieval trial. The extinction protocol consisted of 15 1-min tones at 2-min intervals. (Aiv) Fear memory test in the extinction context on Day 4 (short-term spontaneous recovery). (Av) Fear memory test in the extinction context after 1 mo (long-term spontaneous recovery). (Ai–Aiv) Drug group, n = 19; vehicle group, n = 20. (Av) Drug group, n = 15; vehicle group, n = 16. (Bi–Biii) Freezing during tone-cued conditioning (Bi), retrieval trial (Bii), and extinction (Biii). (Biv) Renewal test conducted in the fear acquisition context (context 2,). Drug group, n = 7; vehicle group, n = 8. (#) Two-way RM ANOVA, P < 0.05, (##) P < 0.01, (*) post-hoc Bonferroni test, P < 0.05.
