Mechanisms of hair cell mechanoelectric transduction: An update

Hair cells, the sensory receptors of the internal ear, are endowed with a transduction machinery poised to detect deflections as small as the breadth of a hydrogen atom. Specialized stereocilia, the hair bundles on the apical surface of hair cells, house the transduction machinery that consists of a mechanically-gated ion channel, a gating spring through which forces are conveyed to the channel, and an adaptation motor (ie, myosin molecules). These components are optimally positioned to ensure that transduction channels detect the most minute forces. By defining the molecular structures that constitute the transduction apparatus and their functional and biochemical properties, insights are gained for developing novel and rational therapies for treating and possibly correcting compromised auditory and vestibular function. This review provides a brief overview of current understanding of the mechanisms related to the perception of hearing and balance that ensue from normal hair cell activities.