Contextual LTM formation after 2 one-trial conditioning trials with an inter-trial interval of 1 h is impaired in αCaMKII autophosphorylation-deficient mice. Means ± s.e.m. are shown. a: WT mice (n = 6) and αCaMKIIT286A mutants (n = 6) were trained twice with a single CS-US pairing (inter-trial interval of 1 h), and then tested 24 h and 48 h after conditioning for contextual and cued LTM formation respectively. The αCaMKIIT286A mutants had impaired contextual LTM formation as they showed significantly less freezing than their WT littermates. b: Forty-eight hours after training cued fear LTM was impaired as the αCaMKIIT286A mutants did not freeze to the tone when tested 48h after conditioning. **, P < 0.01.