Research Article

Ouabain-Induced Apoptosis in Cochlear Hair Cells and Spiral Ganglion Neurons In Vitro

Figure 1

Organotypic cultures from the middle cochleae 72 h after ouabain treatment. The HCs were stained with Alexa Fluor 488-phalloidin. Auditory nerve fibers and SGNs were labeled with an antibody directed against neurofilament 200 and an Alexa Fluor 555 conjugated secondary antibody. (a) Cochlear organotypic culture from postnatal day 3 rat that was cultured for 72 h under normal conditions. (b) Rat cochlear cultures treated with 50 μM ouabain for 72 h. Note that all HCs were intact, whereas the density of the auditory nerve fibers was greatly reduced as compared with the normal control in (a). (c) Cochlear explants were treated with 500 μM ouabain for 72 h. Many SGNs and nerve fibers degenerated and significant percentage’s of HCs were missing. (d) Cochlear cultures treated with 1 mM ouabain for 72 h resulted in complete destruction of both SGNs and HCs in the cochlea (Fluorescence microscope ×200).