ERK5 icKO mice display normal shock sensitivity, acquisition and retrieval of contextual fear memory, yet show reduced contextual fear memory 6 d after training with the 3 × 0.3 mA foot shock paradigm.

<p>A) Schematic depiction of the experimental design. B) Freezing behavior displayed by ERK5 icKO and control mice immediately following each of the 3 successive 0.3 mA foot shocks during training. C) ERK5 icKO mice have acquired and can retrieve contextual fear memory 2 min after training. D) ERK5 icKO mice show reduced contextual fear memory 6 d after training while freezing behavior in the novel context was unaffected.