Observation on Corti's organ of entire cochlea in the guinea pig by scanning electron microscopy.

The entire organ of Corti on guinea pigs were observed by SEM, which has a high resolving power and can be used for a three dimensional study on the fine structure of the cochlea. After the animals were sacrificed, primary perfusion with 3% glutaraldehyde through the oval and round windows was completed in 5 minutes and with 1% OsO4 for the next fixation. After microdissection, the entire organ of Corti was exposed and remained on the modiolus. The OTO technique and critical point drying were used to prepare SEM specimens. The organ of Corti of guinea pig was found to be very similar to that of human being. The basilar membrane widened from the base to the apex of the cochlea. The sensory hair cells, inner and outer, had different appearances marked by shallow U-shaped IHC and W-shaped OHC cilia. The longest layer of OHC cilia left imprints on the undersurface of the tectorial membrane. The relationship between the hair cells and supporting were cells shown. We conclude that the whole specimen of the organ of Corti is more advantageous than piece specimens in acoustic physiological and pathological research by integrated anatomical pattern.