Scanning electron microscopy of nerve fibers in human fetal cochlea
Article first published online: 4 FEB 2005
Copyright © 1990 Wiley-Liss, Inc.
Journal of Electron Microscopy Technique
Volume 15, Issue 2, pages 104–114, June 1990
How to Cite
Hoshino, T. (1990), Scanning electron microscopy of nerve fibers in human fetal cochlea. J. Elec. Microsc. Tech., 15: 104–114. doi: 10.1002/jemt.1060150203
- Issue published online: 4 FEB 2005
- Article first published online: 4 FEB 2005
- Manuscript Revised: 15 DEC 1988
- Manuscript Accepted: 15 DEC 1988
- Manuscript Received: 3 SEP 1988
- Nerve fiber;
- Afferent and efferent nerves;
- Fetal inner ear;
- Human ear;
The cochleas of four human fetuses ranging 22–25 weeks gestation were studied by scanning electron microscopy (SEM) for the purpose of obtaining a better understanding of the nerve fiber arrangement in the human ear. After critical point drying, the specimens were dissected and the floor of the tunnel of Corti and the outer wall of Nuel's space were exposed for observation. Upper cochlear turns, especially the apical turn, seemed to be still immature.
Observed nerve fibers were classified into three types:
- 1Spiral fibers: Fibers traveling basalward and following the shape of the cochlea were found in both the tunnel of Corti and Nuel's space and believed to be the afferent nerves responsible for innervating the outer hair cells
- 2Radial fibers: radiating outward from the osseous spiral lamina—one such radial fiber transversing high in the tunnel space (supposedly the efferent nerve servicing the outer hair cells), and another sort of radial fiber (found crossing the tunnel floor), the nature of which was uncertain.
- 3Irregular fibers: Consisting of thin, randomly running fibers within the cochlea. The destination of these fibers was not determined, but possibly they represent transitory nerve branchings of afferent or more probably efferent nerves, which would later regress during maturation.