NERVE-FIBERS OF THE ENDOLYMPHATIC SAC - ELECTRON-MICROSCOPIC FINDINGSIN THE MONGOLIAN GERBIL

The presence of separate bundles of nerve fibres in the gerbilline end olymphatic sac (ES) is described, paying particular attention to their ultrastructure and localization. One bundle, localized in the area of the subepithelium which separates the sigmoid sinus from the ES, is c omposed only of myelinated fascicles which, moreover, seem to have an isolated contact with the ES area. Other two single nerve fibres, much smaller in caliber, are localized in the ES subepithelium and lateral ly to the ES area, still close to the sigmoid sinus. These fibres, com posed of myelinated and unmyelinated fascicles, seem to have a rather longitudinal orientation and, moreover, contract close relationships w ith the rich vascular network of the ES subepithelial tissue. As far a s the course is concerned, the serial sectioning technique would sugge st that the nerve fibres get very close to the ES epithelial cell laye r, going proximal to distal. Speculations on the origin of this nerve contingent in the ES are proposed and discussed in view of possible ne w theories for pathogenesis and therapy of some inner ear diseases.