A. James Hudspeth, M.D., Ph.D.
Investigator, Howard Hughes Medical Institute
F.M. Kirby Professor and Laboratory of Sensory Neuroscience Head, the Rockefeller University
As the gateway to human communication, the sense of hearing is of enormous importance in our lives. Research on hearing has recently been revolutionized by the demonstration that the ear is not simply a passive receiver for sound, but also an amplifier that augments, filters, and compresses its inputs. Hair cells, the ear’s sensory receptors, use two processes to implement an active process that endows our hearing with these remarkable properties. First, the vibration-sensitive structures of the ear, which are termed hair bundles, display a mechanical instability that underlies their capacity to oscillate in response to stimulation. And second, the membranes of hair cells are replete with proteins that contract in response to electrical stimuli, thus enabling the cells to act like tiny muscles. The exuberant activity of these two motile processes can even cause sounds to be emitted from normal ears.