Selective lesioning of the guinea pig organ of Corti with the use of high frequency current

When experimenting with the electrophysiology of the inner ear there often arises a need, for a variety of reasons, to selectively destroy certain components or portions of the organ of Corti. Common methods of creating cochlear lesions are the use of ototoxic drugs, such as kanamycin, and exposure to intense sounds for prolonged periods of time. A procedure developed by the authors for selective destruction involves the use of high frequency current (1-3 mA at approximately 5MHz) that is passed, for a controlled amount of time, between two electrodes located in the scalae vestibuli and tympani of a particular cochlear turn. A localized region of destruction of elements of the cochlear partition located between the electrode tips, progressing from outer to inner hair cells and to supporting structures, results. Electrophysiological and corresponding histological data from the first, second, and third turns of the guinea pig cochlea are presented and discussed.