A targeted deletion in alpha-tectorin reveals that the tectorial membrane is required for the gain and timing of cochlear feedback

Neuron. 2000 Oct;28(1):273-85. doi: 10.1016/s0896-6273(00)00102-1.

Abstract

alpha-tectorin is an extracellular matrix molecule of the inner ear. Mice homozygous for a targeted deletion in a-tectorin have tectorial membranes that are detached from the cochlear epithelium and lack all noncollagenous matrix, but the architecture of the organ of Corti is otherwise normal. The basilar membranes of wild-type and alpha-tectorin mutant mice are tuned, but the alpha-tectorin mutants are 35 dB less sensitive. Basilar membrane responses of wild-type mice exhibit a second resonance, indicating that the tectorial membrane provides an inertial mass against which outer hair cells can exert forces. Cochlear microphonics recorded in alpha-tectorin mutants differ in both phase and symmetry relative to those of wild-type mice. Thus, the tectorial membrane ensures that outer hair cells can effectively respond to basilar membrane motion and that feedback is delivered with the appropriate gain and timing required for amplification.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acoustic Stimulation
  • Animals
  • Auditory Threshold / physiology
  • Basilar Membrane / physiology
  • Cochlea / physiology*
  • Cochlea / ultrastructure
  • Cochlear Microphonic Potentials / genetics
  • Epithelium / pathology
  • Exons / genetics
  • Extracellular Matrix / genetics
  • Extracellular Matrix / pathology
  • Extracellular Matrix Proteins / deficiency
  • Extracellular Matrix Proteins / genetics*
  • Extracellular Matrix Proteins / metabolism
  • Feedback / physiology
  • GPI-Linked Proteins
  • Gene Targeting*
  • Hair Cells, Auditory / cytology
  • Hair Cells, Auditory, Outer / cytology
  • Hair Cells, Auditory, Outer / physiology
  • Membrane Glycoproteins / deficiency
  • Membrane Glycoproteins / genetics*
  • Membrane Glycoproteins / metabolism
  • Membrane Proteins / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Motion
  • Neurons, Afferent / physiology
  • Otoacoustic Emissions, Spontaneous / physiology
  • Pitch Perception / physiology
  • Tectorial Membrane / metabolism*
  • Tectorial Membrane / pathology

Substances

  • Extracellular Matrix Proteins
  • GPI-Linked Proteins
  • Membrane Glycoproteins
  • Membrane Proteins
  • Otog protein, mouse
  • TECTB protein, human
  • Tecta protein, mouse