Calcium entry into stereocilia drives adaptation of the mechanoelectrical transducer current of mammalian cochlear hair cells

• DOI: 10.1073/pnas.1409920111
• Publication Date: 2014-09-17T04:35:09Z
• Authors: Laura F. Corns; Stuart L. Johnson; Corné J. Kros; Walter Marcotti
• Keywords: 0301 basic medicine; MOUSE COCHLEA; Intracellular Space; Mechanotransduction, Cellular; Ion Channels; ACTIVATION; Stereocilia; QH301; Mice; 03 medical and health sciences; Hair Cells, Auditory; Animals; Egtazic Acid; KINETICS; HEARING; CHANNELS; Hair Cells, Auditory, Inner; INNER-EAR; MECHANOTRANSDUCTION; SENSORY TRANSDUCTION; Adaptation, Physiological; TIME; Hair Cells, Auditory, Outer; RAT; Calcium; Extracellular Space; Ion Channel Gating

Significance

In the inner ear, the sensory receptor cells (hair cells) signal reception of sound. They do so by converting mechanical input, due to sound waves moving the hair bundles on these cells, into electrical current through ion channels situated at the tips of the bundles. To keep the receptors operating at their maximum sensitivity, the current declines rapidly, a process known as adaptation. In nonmammalian vertebrates, Ca 2+ ions entering the mechanosensitive ion channels drive adaptation, but it has been questioned whether this mechanism applies to mammals. We show that adaptation in mammalian cochlear hair cells is, as in other vertebrates, driven by Ca 2+ entry, demonstrating the importance of this process as a fundamental mechanism in vertebrate hair cells.