Figure 2.

PL microstimulation, but not PrCm or ACd, impairs extinction. (A) Microstimulation of PrCm (n = 7) or (B) ACd (n = 7) on Day 2 had no effect on acquisition of extinction or subsequent retrieval of extinction (Day 3) when compared with Unstim group (n = 7; n = 9, respectively). (C) PL microstimulation (n = 11) showed a trend of having a slower rate of extinction on Day 2 when compared with Unstim group (n = 9; P = 0.09). Furthermore, animals that received PL microstimulation on Day 2 had significantly greater recovery of freezing when compared with the Unstim group (Figs. in the right; P < 0.01). (D) IL microstimulation data from Milad et al. (2004) is shown for comparison purposes.