Auditory function cochlea

Streptomycin and gentamicin are more toxic for the vestibular functions of the inner ear than for the cochlea. It has been found that intratympanal administration of streptomycin or gentamicin to 55 patients with Meniere s disease resulted in disappearance of the attacks of dizziness in 95% of cases. In the majority of the patients the auditory functions could be maintained (2 ). 

Compared with aminoglycosides, which caused significant loss of hair cells in the basal turn of the cochlea, ofloxacin caused no loss of hair cells in rats, even at concentrations higher than are achieved clinically (5). Moreover, auditory brainstem testing showed no change in auditory thresholds in the ofloxacin-treated animals, whereas neomycin-treated animals showed substantial threshold shifts. In human studies, topical ofloxacin 0.3% had no demonstrable adverse effects on middle ear or cochlear function and was not associated with any changes in hearing. 

Gubbels SP, Woessner DW, Mitchell JC, Ricci AJ, Brigande JV (2008) Functional auditory hair cells produced in the mammalian cochlea by in utero gene transfer. Nature 455(7212) 537-541... 

Electrodes are the direct interface between the biological structures (auditory neurons) and the electronic system in the CFs. Stimulation electrodes inject charge into the tissue to functionally excite the nerves by electrical stimulation. In other words, electrodes measure the electric potential for charge transfer between solid metal state and electrolyte solution in liquid state inside the cochlea. For better stability implants electrode properties must be evaluated with respect to a biocompatible application for optimum stability, efficacy and life time with a minimum of toxicity. From the material point of view the requirements of an ideal electrode [8-10] might be summarized as follows ... 

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