Characteristics of hearing loss caused by local microcirculatory disorders in cochlea of guinea pigs

Objective To study the characteristics of hearing loss caused by local microcirculatory disorders in the cochlea of guinea pigs. Methods The local microcirculatory disorders in the cochlea basal turn near terminal or in the cupule of cochlea of guinea pigs were induced by photochemical reaction. The morphological changes in the cochlea were observed with light microscopy. The compound action potential N1 (CAPN 1) amplitude, latency, threshold shift evoked by short tone burst were recorded by Madsen 2250 system. Results When the local microcirculatory disorders took place in the cochlea basal turn near terminal, the hearing losses were more remarkable in the high-range frequencies, but with low-range ones to some extent. If the local microcirculatory disorders was induced in the cochlea cupule, the hearing losses were mainly in the low-range frequencies companying with some high-frequency ones. Conclusion Local microcirculatory disorders in the different parts of the cochlea cause different types of hearing loss in different frequency.