UCSF

The tympanic membrane (TM) is the central component of the conductive apparatus of the ear and is the first major organ sound waves hit in the process of being transmitted to the brain. The TM receives sound from the external auditory ear canal (EAC) and appropriately vibrates to transmit this sound to the middle ear. Notably, the TM has the remarkable ability to rapidly repair itself, with perforations typically closing in days to weeks in all mammalian species studied. However, in a subset of cases, these perforations do not close, and patients present with conductive hearing loss. Though this function of the TM has been known for many decades, lack of understanding of the basic biology of the TM has hindered our ability to explain the pathophysiology of chronic perforations because the cellular and molecular mechanisms underlying this repair ability remain largely unknown. This study looked to thoroughly characterize the repair process of the injured TM as epimorphic regeneration and uncover mechanisms of epithelial regeneration that could serve as future targets for treatments for disorders of the tympanic membrane and be applied broadly to epithelial wound repair.