Wildtype mice show no impairments in context or cued fear learning and memory after 2-hit injury.

<p>Wildtype mice (n = 8–10 per group) received a 2-hit frontal impact injury or sham treatment, and underwent cued and contextual fear conditioning 1 month later. (A) On day 1, the sham-treated and 2-hit groups showed comparable amounts of freezing at baseline as well as during and between training trials. BL, baseline (3 min); CS, conditional stimulus (auditory stimulus followed by foot shock); IT, interval between CS (2 min); End, period following last CS (2 min). See <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0115765#s2" target="_blank">methods</a> for additional details. (B, C) Both groups also showed a comparable amount of freezing when they were introduced into the same context on day 2 without receiving an auditory stimulus or foot shock (B) or into a novel environment on day 3 after hearing the auditory stimulus without receiving a foot shock (C). AS, auditory stimulus. One-way ANOVA revealed no significant differences between the groups (A–C). Data are means ± SEM.