Putting ion channels to work: mechanoelectrical transduction, adaptation, and amplification by hair cells.
As in other excitable cells, the ion channels of sensory receptors produce electrical signals that constitute the cellular response to stimulation. In photoreceptors, olfactory neurons, and some gustatory receptors, these channels essentially report the results of antecedent events in a cascade of chemical reactions. The mechanoelectrical transduction channels of hair cells, by contrast, are coupled directly to the stimulus. As a consequence, the mechanical properties of these channels shape our hearing process from the outset of transduction. Channel gating introduces nonlinearities prominent enough to be measured and even heard. Channels provide a feedback signal that controls the transducer's adaptation to large stimuli. Finally, transduction channels participate in an amplificatory process that sensitizes and sharpens hearing.
Hudspeth
A J
AJ
Howard Hughes Medical Institute and Laboratory of Sensory Neuroscience, The Rockefeller University, 1230 York Avenue, New York, NY 10021-6399, USA. hudspaj@rockvax.rockefeller.edu
Choe
Y
Y
Mehta
A D
AD
Martin
P
P
D000222:Adaptation, Physiological; D004558:Electric Stimulation; D006198:Hair Cells, Auditory / Q000502:physiology*; D015640:Ion Channel Gating; D007473:Ion Channels / Q000502:physiology*; D010812:Physical Stimulation
D007473:Ion Channels