A deafness mutation isolates a second role for the tectorial membrane in hearing.
Alpha-tectorin (encoded by Tecta) is a component of the tectorial membrane, an extracellular matrix of the cochlea. In humans, the Y1870C missense mutation in TECTA causes a 50- to 80-dB hearing loss. In transgenic mice with the Y1870C mutation in Tecta, the tectorial membrane's matrix structure is disrupted, and its adhesion zone is reduced in thickness. These abnormalities do not seriously influence the tectorial membrane's known role in ensuring that cochlear feedback is optimal, because the sensitivity and frequency tuning of the mechanical responses of the cochlea are little changed. However, neural thresholds are elevated, neural tuning is broadened, and a sharp decrease in sensitivity is seen at the tip of the neural tuning curve. Thus, using Tecta(Y1870C/+) mice, we have genetically isolated a second major role for the tectorial membrane in hearing: it enables the motion of the basilar membrane to optimally drive the inner hair cells at their best frequency.
Legan
P Kevin
PK
School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, UK.
Lukashkina
Victoria A
VA
Goodyear
Richard J
RJ
Lukashkin
Andrei N
AN
Verhoeven
Kristien
K
Van Camp
Guy
G
Russell
Ian J
IJ
Richardson
Guy P
GP
D000161:Acoustic Stimulation; D000200:Action Potentials; D000818:Animals; D003051:Cochlea / Q000503:physiopathology; D003055:Cochlear Microphonic Potentials; D003638:Deafness / Q000235:genetics / Q000503:physiopathology*; D004056:Differential Threshold; D016326:Extracellular Matrix Proteins / Q000235:genetics*; D058851:GPI-Linked Proteins; D006198:Hair Cells, Auditory / Q000473:pathology; D018072:Hair Cells, Auditory, Outer; D006309:Hearing / Q000502:physiology*; D040542:Mechanotransduction, Cellular; D008562:Membrane Glycoproteins / Q000235:genetics*; D051379:Mice; D008822:Mice, Transgenic; D020125:Mutation, Missense; D017084:Otoacoustic Emissions, Spontaneous; D012405:Round Window, Ear / Q000503:physiopathology; D013680:Tectorial Membrane / Q000473:pathology / Q000502:physiology*
D016326:Extracellular Matrix Proteins; D058851:GPI-Linked Proteins; D008562:Membrane Glycoproteins; C105350:Tecta protein, mouse