Electron Microscopic Observation of Striated Organelle of Vestibular Hair Cells Treated with Tannic Acid

Abstract

Striated organelle (Friedmann body, laminated cytoplasmic inclusion) was first observed in 1963 by Friedmann et al. in the degenerating utricular hair cells from patients with Meniers disease. They reported this Friedmann body, consisting of alternating thick and thin electronopaque lines to form a characteristic pattern, near the surface or within the cytoplasm of degenerating cells. The striated organelles have usually been associated with pathological conditions such as eighth nerve tumors (Hilding and House, 1964) , Conn's syndrome (Friedmann et aI., 1965), drug intoxication (Friedmann et aI., 1966; Jahnke, 1969), or with old age (Rosenhall et aI., 1974). Nevertheless, their consistent occurrence has also been noted in the inner ear hair cells of normal cat (Spoedlin , 1966), squirrel-monkey (Engstrom et aI., 1972), chinchilla (Slepecky et aI., 1980), and rat (Ross and Bourne, 1983). From these reports, striated organelle was proposed to be the normal constituent of hair cells (Slepecky et aI., 1980). Although several possibilities about the role of the striated organelle have been suggested (Slepecky, 1980; Jorgensen, 1982; Ross, 1982), no clear explanation has been achicved. Therefore, it is important to observe more morphological chacteristics of the structure which will become the basis of any functional investigation. In order to obtain the enhanced visibility of the striated organelle, tannic acid which acts as a mordant between osmium treated structure and lead (Simionescu et aI., 1976) was added to glutaraldehyde fixative.