Figure 2.

Fear expression in mice during testing. (A) Four hours after training, only Paired mice froze in response to the auditory tone, and levels of freezing to the training chamber alone was not significant. (B) Recall mice froze significantly more when exposed to the auditory tone 72 h after training. (C) Four hours after training, only Paired mice show a reduction in movement in response to the auditory tone, and there was no significant decrease in movement without tone. (D) Recall mice showed significantly less movement when exposed to the auditory tone 72 h after training. Numbers are expressed as percent time freezing (A and B) or moving (C and D) ± SEM. (**) P < 0.01 and (***) P < 0.001.