The exquisite sensitivity and frequency resolving power of the mammalian inner ear depends upon interactions between the two receptor cells of the organ of Corti, inner (IHC) and outer (OHC) hair cells. While inner hair cells appear to function solely as receptors of acoustic information, OHC’s function both as receptors and effectors, producing motile responses as a function of transmembrane potential fluctuations.
These motile responses modify the mechanical input to the inner hair cells which receive the majority of afferent innervation, thereby enhancing the gross frequency tuning afforded by basilar membrane mechanics. Dr. Joseph Santos-Sacchi studies the effector role of the OHC with electrophysiological (patch clamp) and displacement measurement techniques using isolated OHCs from the guinea pig. He also works on the motor protein (prestin) responsible for the cells’ mechanical activity, utilizing mutational analysis and expression systems to understand how it works.
Specialized Terms: Mammalian inner ear
Hair Cells, Auditory; Ear, Inner; Neurosciences; Otolaryngology; Physiology