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-1Cx30A88V/A88V mice from degeneration and rescues hearing. Here we report the passive compliance of the cochlear partition and active frequency tuning of the basilar membrane are enhanced in the cochleae of CD-1Cx30A88V/A88V compared to CBA/J mice with sensitive high-frequency hearing, suggesting 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 (OHCs) and hence cochlear amplification is greatly reduced in CD-1Cx30A88V/A88V mice. Yet, the saturating amplitudes of cochlear microphonic potentials in CD-1Cx30A88V/A88V and CBA/J mice are comparable. Although not conclusive, these results are compatible with the proposal that OHC transmembrane potentials, determined mainly by potentials extracellular to the OHCs, drive somatic electromotility.

1.
Forge
,
A.
 et al 
J. Comp. Neurol.
467
,
207
231
(
2003
).
2.
Wingard
,
J. C.
&
Zhao
,
H.-B.
Front. Cell. Neurosci.
9
,
202
(
2015
).
3.
Mahendrasingam
,
S.
,
Macdonald
,
J. A.
&
Furness
,
D. N.
J. Assoc. Res. Otolaryngol. JARO
12
,
437
453
(
2011
).
4.
Bosen
,
F.
 et al 
FEBS Lett.
588
,
1795
1801
(
2014
).
5.
Lukashkina
,
V.A.
,
Levic
,
S.
,
Lukashkin
,
A.N.
,
Strenzke
,
N.
,
Russell
,
I.J.
Nat Commun.
8
:
14530
. doi: (
2017
).
6.
Dallos
,
P.
&
Evans
,
B. N.
Science
267
,
2006
2009
(
1995
).
7.
Davis
,
H.
Cold Spring Harb. Symp. Quant. Biol.
30
,
181
190
(
1965
).
8.
Russell
,
I. J.
Nature
301
,
334
336
(
1983
).
9.
Legan
,
P. K.
 et al 
Nat. Neurosci.
8
,
1035
1042
(
2005
).
10.
Mellado Lagarde
,
M. M.
,
Drexl
,
M.
,
Lukashkina
,
V. A.
,
Lukashkin
,
A. N.
&
Russell
,
I. J.
Nat. Neurosci.
11
,
746
748
(
2008
).
11.
Weddell
,
T. D.
 et al 
Curr. Biol. CB
21
,
R682
683
(
2011
).
12.
Johnson
,
S. L.
,
Beurg
,
M.
,
Marcotti
,
W.
&
Fettiplace
,
R.
Neuron
70
,
1143
1154
(
2011
).
14.
Ramamoorthy
,
S.
,
Wilson
,
T. M.
,
Wu
,
T.
&
Nuttall
,
A. L.
Biophys. J.
105
,
2666
2675
(
2013
).
15.
Zidanic
,
M.
&
Brownell
,
Biophys. J.
57
,
1253
1268
(
1990
).
16.
Yu
,
N.
 et al 
Prestin Cell. Mol. Life Sci. CMLS
65
,
2407
2418
(
2008
).
17.
Russell
,
I. J.
 et al 
Nat. Neurosci.
10
,
215
223
(
2007
).
18.
Lukashkina
,
V.A.
,
Yamashit
,
a T.
,
Zuo
,
J.
,
Lukashkin
,
A.N.
,
Russell
,
I.J.
(
2017
). Under review.
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