Extracellular matrices associated with the apical surfaces of sensory epithelia in the inner ear: Molecular and structural diversity
Article first published online: 15 OCT 2002
Copyright © 2002 Wiley Periodicals, Inc.
Journal of Neurobiology
Special Issue: Development and Evolution of Hearing and Balance
Volume 53, Issue 2, pages 212–227, 5 November 2002
How to Cite
Goodyear, R. J. and Richardson, G. P. (2002), Extracellular matrices associated with the apical surfaces of sensory epithelia in the inner ear: Molecular and structural diversity. J. Neurobiol., 53: 212–227. doi: 10.1002/neu.10097
- Issue published online: 15 OCT 2002
- Article first published online: 15 OCT 2002
- Manuscript Accepted: 9 MAY 2002
- Manuscript Received: 29 APR 2002
- Wellcome Trust. Grant Number: 057410/Z/99/Z.
- tectorial membrane;
- inner ear
The ultrastructure and molecular composition of the extracellular matrices that are associated with the apical surfaces of the mechanosensory epithelia in the mouse inner ear are compared. A progressive increase in molecular and structural organization is observed, with the cupula being the simplest, the otoconial membrane exhibiting an intermediate degree of complexity, and the tectorial membrane being the most elaborate of the three matrices. These differences may reflect changes that occurred in the acellular membranes of the inner ear as a mammalian hearing organ arose during evolution from a simple equilibrium receptor. A comparison of the molecular composition of the acellular membranes in the chick inner ear suggests the auditory epithelium and the striolar region of the maculae are homologous, indicating the basilar papilla may have evolved from the striolar region of an otolithic organ. A comparison of the tectorial membranes in the chick cochlear duct and the mouse cochlea reveals differences in the structure of the noncollagenous matrix in the two species that may result from differences in the stochiometry of α- and β-tectorin and/or differences in the post-translational modification of α-tectorin. This comparison also indicates that the appearance of collagen in the mammalian tectorial membrane may have been a major step in the evolution of an electromechanically tuned vertebrate hearing organ that operates over an extended frequency range. © 2002 Wiley Periodicals, Inc. J Neurobiol 53: 212–227, 2002