X-RAY IRRADIATION OF INNER EAR OF GUINEA PIG - EARLY DEGENERATIVE CHANGES IN COCHLEA

X-ray irradiation in single doses was applied to the inner ear of guinea pigs. The organ of Corti was examined by light microscopy using the surface specimen technique as described by Engström. 1. A characteristic pattern of damage was found. The outer hair cells of the two basal coils of the cochlea were extensively degenerated, whereas the outer hair cells of the two apical coils and the inner hair cells were intact. 2. The first sign of degeneration was coarse granulation of the nuclei. 3. Further signs of degeneration were pycnosis of the nuclei, distortion of the normal w-pattern of the hairs and changes in the cuticular region. 4. The first sign of degeneration was found after an interval of three hours from the exposure. 5. Completely degenerated cells were found after an interval of six hours from the exposure. 6. Degeneration was observed following X-ray doses of 4000 R and was found in an increasing scale following exposure to doses of 6000 R and 7000 R. 7. A possible genesis of the degeneration is discussed. © 1969 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.