Pathobiologie/Pathobiochemie Teil 2 - Alex Eberle

Schalltransduktion im Innenohr
An Outer Hair Cell Crowned with an Array
of Stereocilia Connected by Tip Links
The vibrations of the basilar membrane caused by
the oscillations of the perilymph induce shearing of
the tectorial membrane. This leads to bending of the
stereocilia, which stretches the filaments that link
neighboring stereocilia, thereby opening unidentified
potassium channels in the membrane of the
stereocilia through the action of myosin. Myosin 7A
and myosin 15 are probably involved in the
movement of these stereocilia. The protein
diaphanous is also expressed in hair cells, in which it
recruits actin-binding proteins to the cell membrane,
thereby regulating actin dynamics. The myosindiaphanous-actin
cytoskeleton is responsible for the
structural integrity and dynamics of the hair cells.
Otoferlin may be involved in the transport of synaptic
vesicles to the plasma membrane. The potassium
channels formed by the KCNQ4 protein (yellow) and
by the connexins (red) allow recirculation of the
potassium ions from the hair cells to the stria
vascularis and the endolymph. Connexin channels
are shown in red.
16
Willems, New Engl J Med, 2000
26/05/10 Pathobiologie - FS 2010 - Lektion 13 16