FIG. 8.

Conditioned fear memory in NADPH oxidase mutant mice. Mean freezing behavior is shown for contextual and cued fear conditioning tests performed 24 h after training. (A) Wild-type mice versus gp91^phox KO mice showed no difference in mean freezing behavior during either the contextual or cued fear response test (n = 7 mice per genotype, three cohorts; P > 0.05 by Student's two-tailed t test). (B) p47^phox KO mice showed a significant decrease in mean freezing behavior during the contextual fear response test (n = 7 mice per genotype; indicates P < 0.05 by Student's two-tailed t test) but showed no difference in the cued fear response test (n = 7 mice per genotype; P > 0.05 by Student's two-tailed t test).