[Pressure wave-induced damage of the vestibular apparatus in guinea pigs. A transmission electron microscopic study]

Guinea pigs were exposed to pressure wave with a peak pressure value of 175.3dB (SPL). Vestibular test and stereoscopic and TEM observations were performed after the exposure. Vestibular function was normal. Within 48 hours of exposure, slight mechanical injuries of the sensory cells in both the creista and macula were observed, such as displacement of the otolithic membrane, distortion and fusion of cilia and protrusion of the cytoplasm. On the 7th and 14th day, these changes became less marked, but a few cells showed swelling of mitochondria and nerve chalice and abnormalities of afferent nerve terminals, which were supposed to be resulted from metabolic disorders. The significance of these changes was discussed.