Mechanotransduction is required for establishing and maintaining mature inner hair cells and regulating efferent innervation

• Published in: Nature communications Vol. 9; no. 1; pp. 4015 - 15
• Main Authors: Corns, Laura F., Johnson, Stuart L., Roberts, Terri, Ranatunga, Kishani M., Hendry, Aenea, Ceriani, Federico, Safieddine, Saaid, Steel, Karen P., Forge, Andy, Petit, Christine, Furness, David N., Kros, Corné J., Marcotti, Walter
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-10-2018; Nature Publishing Group; Nature Portfolio
• Subjects: 13/106; 13/51; 14/1; 14/19; 14/28; 14/69; 631/378/2619/1533; 631/378/2619/1849; 631/378/3917; 9/74; Acoustics; Action Potentials - physiology; Animals; Auditory Pathways - cytology; Auditory Pathways - metabolism; Auditory plasticity; Auditory system; Cells, Cultured; Channels; Cholinergic Agents - metabolism; Cochlea - cytology; Cochlea - innervation; Depolarization; Efferent Pathways - cytology; Efferent Pathways - metabolism; Functional plasticity; Gerbillinae; Hair; Hair cells; Hair Cells, Auditory, Inner - cytology; Hair Cells, Auditory, Inner - metabolism; Hair Cells, Auditory, Inner - physiology; Hearing; Hearing - physiology; Humanities and Social Sciences; Innervation; Life Sciences; Mechanotransduction; Mechanotransduction, Cellular - genetics; Mechanotransduction, Cellular - physiology; Mice; Mice, Knockout; Morphology; multidisciplinary; Mutation; Neuronal Plasticity - physiology; Neurons and Cognition; Physical characteristics; Proteins; Science; Science (multidisciplinary); Stereocilia - metabolism
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-018-06307-w

In the adult auditory organ, mechanoelectrical transducer (MET) channels are essential for transducing acoustic stimuli into electrical signals. In the absence of incoming sound, a fraction of the MET channels on top of the sensory hair cells are open, resulting in a sustained depolarizing current. By genetically manipulating the in vivo expression of molecular components of the MET apparatus, we show that during pre-hearing stages the MET current is essential for establishing the electrophysiological properties of mature inner hair cells (IHCs). If the MET current is abolished in adult IHCs, they revert into cells showing electrical and morphological features characteristic of pre-hearing IHCs, including the re-establishment of cholinergic efferent innervation. The MET current is thus critical for the maintenance of the functional properties of adult IHCs, implying a degree of plasticity in the mature auditory system in response to the absence of normal transduction of acoustic signals.
Mechanoelectrical transducer (MET) channels on the tips of inner hair cells are essential for transducing auditory sensory information. Here, the authors show that disrupting MET channel function also prevents the preservation of normal inner hair cell identity in adult mice.