Fig. 4. Contextual conditional response was reanalyzed as percent freezing time after separating mice by age into two groups (young adult: 3–6 m; adult: 6.1–14 m) on days 1 and 3 after surgery. Groups are control, anesthesia (A), and surgery. Percent freezing time on day 1. Percent freezing time on day 3 (B ). Values are mean ± SD. N for each group is shown under the bar. There were no statistically significant differences between the age groups for any condition. Hsp72-Tg = heat shock protein 72 transgenic; WT = wild-type C57BL6.