Figure 1.

Delay fear conditioned or naïve groups were anesthetized and prepared for in vivo recordings, where a 20 Hz prefrontal cortex (PFC) train stimulation preceded a single MgN stimulation (A). Delay fear conditioning (DFC) data is graphed in 60 s bins and for both adults (n = 12) and adolescents (n = 15). This consisted of a 6 min baseline, two conditional stimulus (CS)–unconditional stimulus (UCS), and a 4 min post. Arrows indicate the period in which a CS-UCS pairing occurred. The mean percent time freezing increased during and following CS–UCS pairings (B).