Migration Of Neural Precursor Cells Derived From Olfactory Bulb In Cochlear Nucleus Exposed To An Augmented Acoustic Environment

Aims: The regeneration of the auditory neural system remains a challenge in hearing restoration. Acoustic signals may induce a site-specific cell replacement in the auditory system. This hypothesis was tested with grafted implantation of neural precursor cells (NPCs) along the cochlear nucleus in the adult host followed by an augmented acoustic stimulation. Methods: NPCs were obtained from the olfactory bulbs at embryonic day 14–16 and were transplanted into the inside border of cochlear nucleus. Results: The labeled cells survived at least 2 weeks, verified by Hoechst 33342 fluorescence, and by immunostaining for a neuronal marker. In an augmented acoustic environment following implantation the NPCs had migrated directionally to the root of the auditory nerve. Conclusion: This represents the first demonstration that NPCs from OB engraft, migrate, differentiate, and survive in the cochlear nucleus in vivo. Exposure to an augmented acoustic environment after transplantation induced the grafted cells migration towards the root of the cochlear nerve and across auditory fiber of the tz. These cells underwent large-scale differentiation with approximately 10 % of newly generated neurons co-expressing NSE and NeuN, specific markers for neurons. Furthermore, some differentiated neurons expressed glutamate an excitatory, afferent neurotransmitter. These results indicate that adult neural progenitor cells may provide an alternative cell source useful for transplantation therapy in the treatment of auditory neural path disease.