SCANNING ELECTRON MICROSCOPIC STUDY OF DEFENSE ORGANIZATION OF THE COCHLEAR AQUEDUCT TO INFECTION

• Published in: Nippon Jibiinkoka Gakkai Kaiho Vol. 85; no. 6; pp. 674 - 680
• Main Authors: FUTATSUGI, YOSHITAKA, YANAGITA, NORIYUKI, NISHIMURA, SHIGEYASU
• Format: Journal Article
• Language: English
• Published: The Oto-Rhino-Laryngological Society of Japan, Inc 20.06.1982
• ISSN: 0030-6622; 1883-0854
• DOI: 10.3950/jibiinkoka.85.674

A microstructural consideration has been given to the role of the cochlear aqueduct in the inner ear lesions. Guinea pigs were used in this study. In order to induce the lesions physiological salt solution, India ink and staphylococci aureus were injected into the cisterna magna. Staphylococci aureus were injected also into the scala tympani. Then, microstructural changes of the cochlear aqueduct were observed by means of a light microscope and a scanning electron microscope. The following results were obtained. No change was noted by the injection of physiological salt solution into the cisterna magna. By injecting India ink into the cisterna magna, passage was noted via the cochlear aqueduct to the scala tympani in all 100 ears of 50 animals. By injecting staphylococci aureus into the cisterna magna, migrating leukocytes and macrophages tended to increase gradually from the external orifice to the internal orifice of the cochlear aqueduct on the 1st, 3rd and 7th days. Even in the specimen of 7th day after experiment less changes were observed at the internal orifice than at the external orifice. No change was noted in the cribriform structure of the internal orifice. In the scala tympani, only inflammatory cell infiltration was noted in the majority of specimens. Likewise, in the experiment of injection of staphylococci aureus into the scala tympani, inflammatory changes similar to the above-mentioned were noted in the cochlear aqueduct, but the crobriform structure of the internal orifice remained normal. On the contrary, the internal auditory canal showed almost no change compared with the cochlear aqueduct. From the present experimental results, it could be confirmed that the periotic duct tissue of the cochlear aqueduct reacts especially to bacterial infection. The swollen connective tissue forms dense meshwork structure, defending against bacteria and other foreign bodies. Simultaneously, reticular cells, macrophages and leukocytes are hypertrophied by engulfing foreign substances and form dense meshwork structure, fortifying the defense function.