A connexin30 mutation rescues hearing and reveals roles for gap junctions in cochlear amplification and micromechanics.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 28220769.
- Also identified by DOI 10.1038/ncomms14530 and PMC identifier 5321796.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Accelerated age-related hearing loss disrupts high-frequency hearing in inbred CD-1 mice. The p.Ala88Val (A88V) mutation in the gene coding for the gap-junction protein connexin30 (Cx30) protects the cochlear basal turn of adult CD-1Cx30<sup>A88V/A88V</sup> mice from degeneration and rescues hearing. Here we report that the passive compliance of the cochlear partition and active frequency tuning of the basilar membrane are enhanced in the cochleae of CD-1Cx30<sup>A88V/A88V</sup> compared to CBA/J mice with sensitive high-frequency hearing, suggesting that gap junctions contribute to passive cochlear mechanics and energy distribution in the active cochlea. Surprisingly, the endocochlear potential that drives mechanoelectrical transduction currents in outer hair cells and hence cochlear amplification is greatly reduced in CD-1Cx30<sup>A88V/A88V</sup> mice. Yet, the saturating amplitudes of cochlear microphonic potentials in CD-1Cx30<sup>A88V/A88V</sup> and CBA/J mice are comparable. Although not conclusive, these results are compatible with the proposal that transmembrane potentials, determined mainly by extracellular potentials, drive somatic electromotility of outer hair cells.
Medical subject headings
- Cochlea
- Connexin 30
- Gap Junctions
- Hearing
- Mutation, Missense