Figure 2.
CaV1.2 LTCCs modulate cued fear memory extinction. (A) Nifedipine (40 mg/kg) blocked extinction of cued fear in WT mice (n = 6–7). (B) Nifedipine and BayK (4 mg/kg) had no effect on extinction in CaV1.2DHP−/− mice (n = 8–9). Note that no, or only very low levels of freezing were observed in all groups of cued-conditioned mice upon exposure to context alone (trial 0). Data are presented as mean ± SEM. Statistical analysis was performed using 2-way ANOVA. WT mice treated with vehicle showed significantly enhanced freezing behavior compared with nifedipine-treated animals from the sixth presentation onward (6th CS, P < 0.05; 7th–15th CS, P < 0.001). Asterisks indicating significant differences were omitted for clarity.