background outer hair cells' (ohcs') dysfunctions as the extent of temporary and permanent threshold shifts (tts and pts) and cochlear damage were assessed in rabbits exposed to continuous noise methods twelve new zealand white rabbits were studied in noise (n) (n=6; exposed to continuous noise; 95 db spl, 500-8000 hz for 8 h per day during 5 consecutive days) and control (c) (n=6; no...

Inner and outer hair cells were mechanically isolated from the guinea pig cochlea and subjected to stimuli known to induce shape changes in outer hair cells. Depolarization by 70 mM KCl which causes osmotic swelling of outer hair cells also swelled inner hair cells by approximately 8% of their volume. The application of the calcium ionophore ionomycin which induces cortical contractions and elo...

The inner ear not only transduces sound-induced vibration into electrical signals, it also amplifies weak sound to boost its detection. The actuators of this active process are sensory outer hair cells in the organ of Corti, whereas the inner hair cells ensure that the sound-induced signals reach the auditory nerve. However, how the outer hair cells modulate the stimulus to the inner hair cells...

The cochlea not only transduces sound-induced vibration into neural spikes, it also amplifies weak sound to boost its detection. Actuators of this active process are sensory outer hair cells in the organ of Corti, whereas the inner hair cells transduce the resulting motion into electric signals that propagate via the auditory nerve to the brain. However, how the outer hair cells modulate the st...

A large proportion of age-related hearing loss is caused by loss or damage to outer hair cells in the organ of Corti. The organ of Corti is the mechanosensory transducing apparatus in the inner ear and is composed of inner hair cells, outer hair cells, and highly specialized supporting cells. The mechanisms that regulate differentiation of inner and outer hair cells are not known. Here we repor...

The remarkable hearing capacities of mammals arise from various evolutionary innovations. These include the cochlear outer hair cells and their singular feature, somatic electromotility, i.e., the ability of their cylindrical cell body to shorten and elongate upon cell depolarization and hyperpolarization, respectively. To shed light on the processes underlying the emergence of electromotility,...

Auditory function in the mammalian inner ear is optimized by collaboration of two classes of sensory cells known as inner and outer hair cells. Outer hair cells amplify and tune sound stimuli that are transduced and transmitted by inner hair cells. Although they subserve distinct functions, they share a number of common properties. Here we compare the properties of mechanotransduction and adapt...

Mammalian hearing relies upon active cochlear mechanics, which arises from outer hair cell electromotility and hair bundle movement, to amplify acoustic stimulations increasing hearing sensitivity and frequency selectivity. Here we describe the novel finding that gap junctions between cochlear supporting cells also have a critical role in active cochlear amplification in vivo. We find that targ...