The outer hair cell

The outer hair cells combine sensory function
with the ability to elongate and contract when
acoustically stimulated. The apical pole of a hair
cell carries an array of about 100 cylindrical
stereocilia in a V-shaped arrangement. Each
stereocilium contains an actin molecule, which
enables it to elongate or to contract. The tips of
the stereocilia are connected by tip links. The
potassium channels are formed by the KCNQ4
protein (yellow) and by connexins (red). Important
for the structural integrity and dynamics of
the hair cells is a cytoskeleton involving actin,
myosin 7A, myosin 15, and the protein diaphanous.