Figure 7.

Effects of post-extinction CA1 or CA3 lesions on fear conditioning, extinction, and testing (Experiment 2). (A) Percentage of freezing during the fear conditioning session for the three groups of rats. Freezing is shown for the 3-min period prior to the first trial (baseline) and during 1-min periods after each conditioning trial. (B) Percentage of freezing during the extinction sessions for the three groups of rats. Freezing was averaged across the 1-min periods after the first four CS presentations across the 3 d of extinction. Although lesion group designations are indicated in A and B, the rats had not undergone surgery at this point in training. (C) Normalized conditional freezing across the retention test (CS freezing − baseline). Rats were tested either in the extinction context (SAME; open bars) or outside of the extinction context (DIFF; filled bars). Neurotoxic CA1, CA3, or sham (SH) lesions were made after extinction. All data are presented as mean ± SEM.