Figure 3.

Comparison of Auditory Brain Stem Response (ABR) measures in separate groups of UM-HET4 mice, assessed at 5-7 months (15 mice), 22-24 months (26 mice) and 27-29 months (22 mice) of age respectively. A small but significant increase (p<0.01) in the mean of auditory ABR thresholds at 4 kHz is seen at 22-24 months compared to 5-7 months, no significant changes were seen at other frequencies. At 27-29 months of age there were significant elevations (p<0.01) in the means of ABR thresholds at all four frequencies tested either when compared to 5-7 months mice or 22-24 months. These mice were also used for the gap detection and morphological assays described in this manuscript. Asterisks indicate significance (p<0.01). Significance was tested using the Student t test (Sigmaplot)