Ouabain-Induced Apoptosis in Cochlear Hair Cells and Spiral Ganglion Neurons In Vitro
Figure 2
Representative cochleograms that show the percentage of missing IHCs and OHCs following ouabain treatment. No evidence of missing HCs was found ((a) and (b)). Panels (a) and (b) show the mean cochleograms (average of ) at 24 h and 48 h following 50 μM ouabain treatment, respectively. However, approximately 20% of IHCs were missing at the basal turn of the cochlea (c), which shows the mean cochleogram at 72 h after treatment with 50 μM ouabain. (d), (e), and (f) show the mean cochleograms at 24 h, 48 h, and 72 h after treatment with 500 μM ouabain, respectively. Note that the loss in HCs progresses from the base to the apex in a time-dependent manner. In addition, loss in IHCs was greater than OHCs. (g), (h), and (i) represent the mean cochleograms at 24 h, 48 h, and 72 h after treatment with 1000 μM ouabain. At 24 h after 1000 μM ouabain treatment, approximately 85% of IHCs and 50% of OHCs were missing (g). When the culture period was extended to 48 h, most IHCs and OHCs were no longer present, with the notable exception of the tip of the apex (h). Treatment with 1000 μM ouabain for 72 h destroyed 100% of HCs (i).
