Mechanical stimuli generated by head movements and changes in sound pressure are
detected by hair cells with amazing speed and sensitivity. The mechanosensitive organelle,
the hair bundle, is a highly elaborated structure of actin-based stereocilia arranged in
precise rows of increasing height. Extracellular linkages contribute to its cohesion and
convey forces to mechanically gated channels. Channel opening is nearly instantaneous
and is followed by a process of sensory adaptation that keeps the channels poised in their …