X-Ray Irradiation of the Inner Ear Of the Guinea Pig: Early Degenerative Changes In The Vestibular Sensory Epithelia

Abstract

X-ray irradiation in single doses was applied to the inner ear of guinea pigs. The vestibular sensory epithelia were examined by light microscopy using the surface specimen technique. 1. The degeneration of sensory cells was found after exposure to 6000 R and 7000 R. 2. The sensory cells in the periphery of the cristae ampullares and the maculae sacculi and utriculi were most susceptible to damage. 3. The number of degenerated sensory cells was slightly higher in the cristae ampullares and the macula utriculi than in the macula sacculi. 4. Most of the degenerated sensory cells seemed to be of the type II. 5. The first sign of degeneration was a coarse granulation of the nucleus. 6. Further signs of degeneration were pycnosis of the nucleus and a spiderlike structure in the cuticular region. 7. The first sign of degeneration was found after an interval of three hours from the exposure. 8. Completely degenerated cells were found after an interval of eighteen hours from the exposure. 9. No pathological changes were noted in the supporting cells. 10. Exposure to 2000 R and 4000 R was not followed by visible changes.