Abstract
Hearing and balance disorders are included in most common disabilities, and the majority is incurable because of the low capability for regeneration of the inner ear. New therapeutic approaches including cell transplantation are therefore subjected to overcome degenerative diseases of inner ears. Firstly, transplantation of neural stem cells (NSCs) into inner ears has been attempted as well as the retina. Grafted NSCs can survive and migrate into inner ear tissues including sensory epithelia after transplantation into inner ears of newborn rats. Histological analysis following transplantation of NSCs into injured, matured inner ears of mice demonstrates the potential of NSCs for replacement of inner ear hair cells or primary neurons. In vitro analysis also support the hypothesis that NSCs can differentiate into inner ear hair cells. In addition, NSC-derived cells have the potential for producing several neurotrophins in the inner ear, suggesting the potential of NSC transplantation for protection of inner ear tissues from degeneration.
