Department of Neuroscience, University of Virginia, PO Box 801392, Charlottesville, VA 22908, USA.
Active feedback mechanisms in the ears of mammals amplify and tune the auditory response to sound stimuli, allowing these organisms to enjoy both exquisite sensitivity and sharp frequency selectivity. A requisite component of this feedback pathway has recently been identified. Targeted deletion of pres, the gene that encodes the novel membrane-bound motor protein prestin, has revealed a hundred-fold loss in hearing sensitivity suggesting that it might be part of the elusive cochlear amplifier.