Electroretinography (ERG) of X. laevis tadpoles treated with HDACi's. A, B-wave amplitudes obtained from VPA-treated and untreated WT and P23H X. laevis tadpoles in response to flashes of increasing intensities. Two-way ANOVA shows a significant effect of intensity and group (p = 7 × 10−17, p = 4.1 × 10−4). n = 5–7 animals per condition. Multiple comparisons (Tukey's test) showed that P23H untreated responses were significantly different from all other groups (p < 0.019) and no other differences between groups were significant. B, Representative ERG traces from each condition in A. C, B-wave amplitudes obtained from sodium butyrate (NaBu)-treated and untreated P23H X. laevis tadpoles in response to increasing flash intensities. Two-way ANOVA showed a significant effect of intensity and group (p = 1.1 × 10−6, p = 0.012). Responses from treated P23H X. laevis improved significantly. D, Representative ERG traces from each condition in C. n = 4–8 animals per condition. Error bars indicate SEM.