Figure 3

Sensory Gating is Impaired in SRKO mice. Sensory gating was measured in the frontal cortex EEG of SRKO mice (n = 10) and WT littermates (n = 9) by averaging the evoked response potential (ERP) of 100 repetitions of two identical 5 kHz 50 ms tones (S1 and S2) separated by 500 ms. Frontal cortex grand average ERP’s are superimposed in (A) for WT (left) and SRKO (right) animals. Although N40 was larger in S1 than S2 for all animals, only WT animals had significantly larger P20 and P20–N40 amplitudes in S1 than in S2 (B,C). The P20–N40 amplitude was normalized as a ratio between ERP1 (from S1) and ERP2 (from S2) before comparing between groups. Compared to WT littermates, SRKO mice had a reduced gating response of P20–N40 amplitude in the frontal cortex as evidenced by a larger S2/S1 ratio (D) and an attenuated difference between S1 and S2 P20–N40 amplitudes (E). Stars in (B) and (C) represent a main effect of stimulus in a two-way RM ANOVA (N40) or significance in a Holm–Sidak post hoc test following a significant interaction in a two-way RM ANOVA (P20, P20–N40). Stars in (D) and (E) represent significance in an unpaired two-tailed Welch’s t-test.