The tectorial membrane: one slice of a complex cochlear sandwich.

Purpose of review: The review is both timely and relevant, as recent findings have shown the tectorial membrane plays a more dynamic role in hearing than hitherto suspected, and that many forms of deafness can result from mutations in tectorial membrane proteins. Recent findings: Main themes covered are (i) the molecular composition, structural organisation and properties of the tectorial membrane, (ii) the role of the tectorial membrane as a second resonator and a structure within which there is significant longitudinal coupling, and (iii) how mutations in tectorial membrane proteins cause deafness in mice and men. Implications: Findings from experimental models imply that the tectorial membrane plays multiple, critical roles in hearing. These include coupling elements along the length of the cochlea, supporting a travelling wave and ensuring the gain and timing of cochlear feedback are optimal. The clinical findings suggest stable, moderate-to-severe forms hereditary hearing loss may be diagnostic of a mutation in TECTA, the gene encoding one of the major, non-collagenous proteins of the tectorial membrane.