Figure 1.

A seizure before learning selectively impairs hippocampal trace memory. A, Timeline of trace fear conditioning experiments. B, The mice that experienced a seizure (n = 10) before training did not differ in freezing levels compared to control (n = 10) mice when the tone was presented again 24 h later in a novel context. C, However, by 1 week after the seizure, mice in the seizure group froze significantly less than those in the control group in the novel context during the tone presentation. Similar to the results in experiment 1 at 1 week there was a significant reduction in freezing in experiment 2 when mice were presented with the tone at one week (D) and 2 weeks (E) after a seizure and learning (control = 10; seizure = 10). F, In our third trace fear experiment in which mice were tested only 2 weeks after a seizure and learning, the seizure (n = 11) group froze significantly less than the control (n = 11) group when presented with the tone in a new context. The bars represent the mean and the error bars indicate standard error of the mean (SEM). * p < .05, ** p < 0.01, *** p < 0.001.