The protective effect of olfactory ensheathing cells on post-injury spiral ganglion cells.

CONCLUSIONS: Transplantation of OECs into the cochlea may protect and increase the survival of SGCs.

OBJECTIVE: To investigate the protective effect of the transplantation of olfactory ensheathing cells (OECs) on injured spiral ganglion cells (SGCs) in rats.

METHODS: OECs were transplanted into the cochlea in rats with SGCs that were injured by kanamycin sulfate (KM). An equal volume of D-Hanks was injected into the cochlea of control rats. Auditory brainstem responses (ABRs) were recorded from the rats in both groups to monitor changes in hearing thresholds. Immunofluorescence was employed to examine the density and morphology of SGCs to assess the ototoxic condition of the cochlea.

RESULTS: There was no significant difference in the ABR threshold at each frequency between the control and experimental groups. Notably, in the experimental group, a number of Hoechst 3334-labeled nuclei were detected from the apex to the basal turn of the cochlea, demonstrating that the OECs were successfully transplanted and survived in the cochlea. In the experimental group, most of the SGCs were tightly arranged, and the nuclear membrane, chromatin, and nucleolus were all clear. The SGCs in the control group were loosely arranged, and only a few normal SGCs were observed in this group.