[Effect of the spiral ganglion cell and nerve fiber of rat cochlea in vitro to hypoxia].

OBJECTIVE

To establish a practical model for Wistar rat cochlea organ culturing in vitro, and to observe the growing status in hypoxia of the spiral ganglion cell and nerve fiber.

METHODS

We used an in vitro hypoxia model and dissociated cultures of the basal membrane from the cochlea of 3-day-old Wistar rats. And put them in incubator (37 degrees C, 90% N2, 5% CO2, 5% O2) to hypoxia culture for different times. The culture were Immunofluorescence dyed and count the number of the spiral ganglion cell and the cell density in unit area (24 mm x 36 mm), and observe the morph of nerve fiber under the confocal microscope, the results were compared with controls.

RESULTS

Hypoxia early (6 h) nerve fiber appear edema, spiral ganglion cell didn't change compared with controls; nerve fiber appear break and disintegration and the spiral ganglion cell decrease in 12 hours culturing, and the cell density in unit area had remarkable difference compared with control (P < 0.01). Hypoxia leads to the cell density decrease in a time-dependent manner, the longer of cultures times in hypoxia, the heavier of damage in spiral ganglion cell and nerve fiber. Twelve hours culturing, and the cell density in unit area had remarkable difference compared with control (P < 0.01). Hypoxia leads to the cell density decrease in a time-dependent manner, the longer of cultures times in hypoxia, the heavier of damage in spiral ganglion cell and nerve fiber.

CONCLUSIONS

The study findings suggest that hypoxia makes the spiral ganglion cell and nerve fiber damage of culturing in vitro, and nerve fiber more susceptible than spiral ganglion cell for hypoxia.