Figure 5.

NT immunostaining and immunostaining index in the spiral ligament. Examples of NT immunostaining images obtained from the spiral ligament in the middle turn of cochleae in the normal control (a), the noise exposure (B), and the noise/treatment (c) groups by confocal microscopy. No significant NT immunostaining was found in the spiral ligament of the normal control group (A). A large number of NT positive cells were found in the spiral ligament of the noise exposure group (arrows in (b)) while a significantly decreased number of NT positive cells were found in the noise/treatment group (arrows in (c)). The results of the immunostaining index are shown in (d). A high NT immunostaining index was found in the spiral ligament in all three turns of the noise exposure group. There were significant differences between the normal control and the noise exposure groups in the cochlear three turns, and between the noise exposure and the noise/treatment groups in the basal and middle turns. There was no significant difference between the noise exposure and the noise/treatment groups in the apical turn. The numbers (1, 2, 3) in (d) indicate the normal control, noise exposure, and noise/treatment groups, respectively (*** and ** indicate P < 0.001 and <0.01, resp.). Scale bar = 20 μm in (c) for (a)–(c) (error bars represent standard error of the means. Number of cochleae = 6 in each group).