Macromolecular and electrical coupling between inner hair cells in the rodent cochlea

Inner hair cells (IHCs) are the primary receptors for hearing. They are housed in the cochlea and convey sound information to the brain via synapses with the auditory nerve. IHCs have been thought to be electrically and metabolically independent from each other. We report that, upon developmental maturation, in mice 30% of the IHCs are electrochemically coupled in 'mini-syncytia'. This coupling permits transfer of fluorescently-labeled metabolites and macromolecular tracers. The membrane capacitance, Ca2+-current, and resting current increase with the number of dye-coupled IHCs. Dual voltage-clamp experiments substantiate low resistance electrical coupling. Pharmacology and tracer permeability rule out coupling by gap junctions and purinoceptors. 3D electron microscopy indicates instead that IHCs are coupled by membrane fusion sites. Consequently, depolarization of one IHC triggers presynaptic Ca2+-influx at active zones in the entire mini-syncytium. Based on our findings and modeling, we propose that IHC-mini-syncytia enhance sensitivity and reliability of cochlear sound encoding.

Medienart:

E-Artikel

Erscheinungsjahr:

2020

Erschienen:

2020

Enthalten in:

Zur Gesamtaufnahme - volume:11

Enthalten in:

Nature communications - 11(2020), 1 vom: 25. Juni, Seite 3208

Sprache:

Englisch

Beteiligte Personen:

Jean, Philippe [VerfasserIn]
Anttonen, Tommi [VerfasserIn]
Michanski, Susann [VerfasserIn]
de Diego, Antonio M G [VerfasserIn]
Steyer, Anna M [VerfasserIn]
Neef, Andreas [VerfasserIn]
Oestreicher, David [VerfasserIn]
Kroll, Jana [VerfasserIn]
Nardis, Christos [VerfasserIn]
Pangršič, Tina [VerfasserIn]
Möbius, Wiebke [VerfasserIn]
Ashmore, Jonathan [VerfasserIn]
Wichmann, Carolin [VerfasserIn]
Moser, Tobias [VerfasserIn]

Links:

Volltext

Themen:

Journal Article
Research Support, Non-U.S. Gov't

Anmerkungen:

Date Completed 28.08.2020

Date Revised 25.06.2021

published: Electronic

Citation Status MEDLINE

doi:

10.1038/s41467-020-17003-z

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM311655351