Normal audiogram but poor sensitivity to brief sounds in mice with compromised voltage-gated sodium channels (Scn8a medJ)

Hear Res. 2019 Mar 15;374:1-4. doi: 10.1016/j.heares.2019.01.001. Epub 2019 Jan 4.

Abstract

The Scn8amedJ mutation of the gene for sodium channels at the nodes of Ranvier slows nerve conduction, resulting in motor abnormalities. This mutation is also associated with loss of spontaneous bursting activity in the dorsal cochlear nucleus. However initial tests of auditory sensitivity in mice homozygous for this mutation, using standard 400-ms tones, demonstrated normal hearing sensitivity. Further testing, reported here, revealed a severely compromised sensitivity to short-duration tones of 10 and 2 ms durations. Such a deficit might be expected to interfere with auditory functions that depend on rapid processing of auditory signals.

Keywords: Auditory mutations; Behavioral testing; Hearing; Sodium channels; Temporal summation; medJ.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Acoustic Stimulation
  • Animals
  • Audiometry, Pure-Tone
  • Auditory Threshold / physiology*
  • Cochlear Nucleus / physiopathology
  • Hearing Tests
  • Homozygote
  • Mice
  • Mice, Inbred C3H
  • Mice, Inbred C57BL
  • Mice, Mutant Strains
  • Mutation*
  • NAV1.6 Voltage-Gated Sodium Channel / deficiency*
  • NAV1.6 Voltage-Gated Sodium Channel / genetics*
  • NAV1.6 Voltage-Gated Sodium Channel / physiology
  • Neural Conduction / genetics
  • Neural Conduction / physiology
  • Ranvier's Nodes / physiology
  • Time Factors

Substances

  • NAV1.6 Voltage-Gated Sodium Channel
  • Scn8a protein, mouse