Auditory sensory cells (hair cells) are responsible for sound transduction in the cochlea of the inner ear. In the presence of a longitudinal a.c. field isolated living outer hair cells showed reversible motile responses. They followed the stimulus up to at least 1 kHz. Control experiments in the presence of cytochalasin B, phalloidin and dinitrophenol excluded actomyosin as a molecular basis o...

The effect of permanent noise-induced hearing loss on the auditory brainstem response (ABR) and the micromechanical properties of cochlear hair cell stereocilia in guinea pigs was investigated. The threshold of movement of the stereocilia was measured by applying force from a fluid filled pipette. After exposure to a 1.0 kHz pure tone signal at 105 dB(A) for 72 h the threshold of the ABR was br...

The auditory system transduces sound-evoked vibrations over a range of input sound pressure levels spanning six orders of magnitude. An important component of the system mediating this impressive dynamic range is established in the cochlear sensory epithelium, where functional subtypes of cochlear nerve fibers differ in threshold sensitivity, and spontaneous discharge rate (SR), by more than a ...

Cisplatin is a widely used chemotherapy drug, despite its significant ototoxic side effects. To date, the mechanism of cisplatin-induced ototoxicity remains unclear, and hearing preservation during cisplatin-based chemotherapy in patients is lacking. We found activation of the ATM-Chk2-p53 pathway to be a major determinant of cisplatin ototoxicity. However, prevention of cisplatin-induced ototo...

tory canal. The external auditory canal then channels the vibration toward the eardrum, or tympanic membrane (TM). This in turn causes the eardrum to vibrate, which sets into motion the mechanical structures of the middle ear. The middle ear ossicles, or middle ear bones. These 3 tiny bones are attached to the TM and move as it moves. They transmit the sound waves further along the auditory cha...

Robertson, Donald and Bardia Paki. Role of L-type Ca channels in transmitter release from mammalian inner hair cells. II. Single-neuron activity. J Neurophysiol 87: 2734–2740, 2002; 10.1152/jn.00327.2001. Previously reported changes in the gross sound-evoked cochlear potentials after intracochlear perfusion of nimodipine suggest that dihydropyridine-sensitive Ca channels (L-type) control the so...

GM3 synthase (ST3GAL5) is the first biosynthetic enzyme of a- and b-series gangliosides. Patients with GM3 synthase deficiency suffer severe neurological disability and deafness. Eight children (ages 4.1 ± 2.3 years) homozygous for ST3GAL5 c.694C>T had no detectable GM3 (a-series) or GD3 (b-series) in plasma. Their auditory function was characterized by the absence of middle ear muscle reflexes...

BACKGROUND Current attempts to regenerate cochlear sensorineural structures motivate further inspection of the human organ of hearing. Here, we analyzed the supernumerary inner hair cell (sIHC), a possible sign of regeneration and cell replacement. METHODS Human cochleae were studied using field emission scanning electron microscopy (FESEM; maximum resolution 2 nm) obtained from individuals a...

In sensory hair cells of auditory and vestibular organs, the ribbon synapse is required for the precise encoding of a wide range of complex stimuli. Hair cells have a unique presynaptic structure, the synaptic ribbon, which organizes both synaptic vesicles and calcium channels at the active zone. Previous work has shown that hair-cell ribbon size is correlated with differences in postsynaptic a...

Three different auditory representations—Lyon’s cochlear model, Patterson’s gammatone filterbank combined with Meddis’ inner hair cell model, and mel-frequency cepstral coefficients—are analyzed in connection with self-organizing maps to evaluate their suitability for a perceptually justified classification of sounds. The self-organizing maps are trained with a uniform set of test sounds prepro...