Chapter 49 - Hair Cell Regeneration in the Inner Ear and Lateral Line

Abstract

In vertebrates, the ability to perceive sound, motion, and gravity is mediated through specialized mechanosensory hair cells located in the inner ears of all vertebrates and in the lateral line system of aquatic vertebrates. Although the physical structures of hair cells and hair cell sensory epithelia are grossly similar in all vertebrates, only mammals have lost the ability to regenerate hair cells. Studies of the regenerative response in other vertebrates, in particular zebrafish, and of the development of the inner ear in mammals have identified common cellular and molecular processes that regulate hair cell formation. In particular, the Wnt and Notch signaling pathways and the transcription factor Atoh1 have important roles in hair cell formation under most circumstances. Attempts to induce regeneration in adult mammals through directly regulating these pathways are ongoing. Although some preliminary results are encouraging, additional work will be required to achieve functional recovery.