Increased freezing to unconditioned tones in Kv4.2 knockout (KO) mice. (A) During conditioning KO mice froze more than wild-type (WT) controls during the first (before conditioning) and second conditioned stimulus (CS) presentation trials. (B) Genotypes showed equivalent initial freezing and similar reductions in freezing from the first to the last five CS trial block during extinction training. Genotypes did not differ in freezing during (C) extinction retrieval or (D) fear renewal. Data are mean ± SEM; n = 8-12/genotype. *P < 0.05; **P < 0.01.
Kiselycznyk et al. Biology of Mood & Anxiety Disorders 2012 2:5 doi:10.1186/2045-5380-2-5