Merck
  • Home
  • Search Results
  • Macromolecular and electrical coupling between inner hair cells in the rodent cochlea.

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

Nature communications (2020-06-27)
Philippe Jean, Tommi Anttonen, Susann Michanski, Antonio M G de Diego, Anna M Steyer, Andreas Neef, David Oestreicher, Jana Kroll, Christos Nardis, Tina Pangršič, Wiebke Möbius, Jonathan Ashmore, Carolin Wichmann, Tobias Moser
ABSTRACT

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.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Magnesium sulfate heptahydrate, puriss. p.a., ACS reagent, ≥99.0% (KT)
Sigma-Aldrich
4-Aminopyridine, 98%
Sigma-Aldrich
D-(+)-Glucose, ≥99.5% (GC)
Sigma-Aldrich
HEPES, ≥99.5% (titration)
Sigma-Aldrich
Carbenoxolone disodium salt, ≥98%
Supelco
Flufenamic acid, analytical standard, for drug analysis
Sigma-Aldrich
Adenosine 5′-triphosphate magnesium salt, ≥95%, bacterial
Sigma-Aldrich
Ethylene glycol-bis(2-aminoethylether)-N,N,N′,N′-tetraacetic acid, for molecular biology, ≥97.0%
Sigma-Aldrich
1-Octanol, anhydrous, ≥99%
Sigma-Aldrich
Adenosine 5′-triphosphate disodium salt hydrate, Grade I, ≥99%, from microbial
Sigma-Aldrich
Cesium chloride, Grade I, ≥99.0%
Sigma-Aldrich
Tetraethylammonium chloride, ≥98% (titration)
Sigma-Aldrich
Cesium methanesulfonate, used in patch clamp techniques
Sigma-Aldrich
(+)-Catechin hydrate, ≥98% (HPLC), powder
Sigma-Aldrich
Lucifer Yellow CH dilithium salt, fluorescent stain
Sigma-Aldrich
L-Glutathione reduced, ≥98.0%
Sigma-Aldrich
Glucose-Udp-Fluorescein Conjugate
Sigma-Aldrich
Suramin sodium salt, ≥98% (TLC)
Sigma-Aldrich
L-Glutamine, ReagentPlus®, ≥99% (HPLC)