LVII Circulation of the Inner Ear Fluids

Abstract

Corti, in 18 51, 1 described the cells of the stria vascularis and sug gested that they might be the structure for secreting endolymph. Also in 1851 Reissner 2 described the membrane which now bears his name and divides the scala vestibuli from the scala media, showing anatomically that the membranous labyrinth is a closed system. Fol lowing this observation there has been much speculation concerning the characteristics of the endolymphatic and perilymphatic fluids. In 1927 Stacy Guild 3 performed an experiment which he felt fur nished sufficient evidence to indicate the nature of fluid flow within the scala media.Through a small pipette Guild injected a solution of potassium ferrocyanide and iron ammonium citrate into the scala media of sev eral living guinea pigs. After the lapse of various time intervals, the animals were sacrificed and the acid in the fixation fluid precipitated prussian blue granules in sites along the scala media. The temporal bones of these animals were then sectioned and mounted serially so that the location of the granules could be studied with the micro scope. In 16 of 20 animals the blue granules were found in the walls of the endolymphatic sac. From this he concluded that the flow of endolymph was from the stria vascularis down the scala media through the canalis reuniens to the saccule ending finally in the endolymphatic

Perilymph Kinetics of FITC-Dextran Reveals Homeostasis Dominated by the Cochlear Aqueduct and Cerebrospinal Fluid

“…Volume uptake into endolymph. In classical texts, it was suggested that endolymph was generated by Bradial flow^involving volume and water movements across Reissner's membrane (Naftalin and Harrison 1958;Lawrence et al 1961). In view of extremely low measured endolymph flow rates (0.36 nL/min mean rate toward the base) , it is now generally accepted that endolymph is not secreted in volume.…”

Scanning Electron Microscopy of the Endolymphatic Sac Epithelium

“…The first detailed experimental investigation was by He postulated that endolymph is formed by the stria vascularis of the cochlear duct and absorbed in the endolymphatic sac. This theory was supported by the following investigators ( Yamakawa, 1929;Anderson, 1948;Engstrom and Hjorth, 1950), while others believed that endolymph is absorbed elsewhere (Altmann and Waltner, 1950;Lawrence et al, 1961;Rauch et al, 1963). The presumptive importance of the endolymphatic sac in Meniere's disease has also been discussed (Portmann, G., 1927, Portmann, M., 1964House, 1962).…”

Mechanism of the Ménière Attack

“…This assumption is based on von Bekesy's observation that a fistula in Reissner's membrane rapidly changed the appearance of the under lying hair cells and that they soon ceased functioning. Other workers (4,(12)(13)(14)26) extended these experiments with the purpose of finding out if this hair cell damage could be widened to adjacent regions. The results were always the same, the damage was limited to the immediately underlying hair cells.…”