Figure 7.

qRT-PCR results comparing gene expression of Ntf3, Bdnf and Gdnf at 5-7 months versus 22-24 months (A) and at 5-7 months versus 27-29 months (B), in whole cochleae from pooled samples (from 2-3 right cochleae) of UM-HET4 mice (5 pools from 5-7 month old mice, 14 pools from 22-24 month old mice; 5 pools from 27-29 month old mice). Ntf3 gene expression in 22-24 month old animals was significantly decreased compared to 5-7 month old mice (p < 0.02). At 27-29 months of age, Ntf3 expression remained significantly decreased from 5-7 month old animals.. Compared to 5-7 months, the decrease in Bdnf expression was not significant at 22-24 months, but became significant in the 27-29 months old animals (p< 0.01). There were no significant changes in Gdnf expression. Significance was determined using an ANOVA with a Bonferroni/Dunn Post-hoc test (Statview) comparing the Δ₁ values of the young animals to the the Δ₁ values of the older animals. The error was calculated using the standard deviation of the Δ₁ as 2^{−(Δ₁Δ₂Ct-stdev)} and2^{−(Δ₁Δ₂Ct+stdev)}.