Predisposition for and Prevention of Subjective Tinnitus Development
Figure 10
Intensity functions of brainstem and cortical responses in NT and T animals. A
Brainstem responses (RMS of ABR amplitudes) of NT animals over the different stimulation intensities grouped for frequencies below the trauma, frequencies affected most by the trauma and frequencies above the trauma affected range. Given is the interaction of the 2-factorial ANOVA of measurement time (pre or post trauma) and intensities, Whiskers give the SEM, asterisks indicate significant Tukey post-hoc tests. No interaction is found here while the mean over all intensities (insets) indicates a significant decrease of ABR response after the trauma for frequencies below 2 kHz. B Mean rate-intensity functions of the evoked responses of the neurons in AI in NT animals plotted the same way as in A, the gray area indicates the iso-intensity measurement range shown, e.g., in Figure 6. The interaction is significant in all three cases indicating intensity specific changes while over all intensities only the activity below the trauma drops significantly. C ABR of T animals, no significant interaction could be found, but mean over all intensities the ABR amplitudes increase in all frequency ranges. D Mean rate-intensity functions of neurons in AI of T animals, the interaction is significant for the lower two frequency ranges indicating intensity specific changes without a general increase of activity. This can only be found above the trauma in the range of the tinnitus frequencies. Tukey post-hoc test significance level: * p<0.05, ** p<0.01, *** p<0.001.