Functional significance of dendritic swelling after loud sounds in the guinea pig cochlea

Hear Res. 1983 Mar;9(3):263-78. doi: 10.1016/0378-5955(83)90031-x.


Exposure of the guinea pig cochlea to loud pure tones caused a dramatic swelling of afferent dendrites beneath the inner hair cell (IHC). This swelling occurred in a restricted region of the cochlea basalward of the exposure frequency location. For a 110 dB tone swelling was just detectable in 1 micron sections for a 18 3/4 min exposure and was clearly visible after a 22 1/2 min exposure. Swelling was reversible. Exposures which caused swelling produced a loss in sensitivity of the flat low frequency 'tail' of the frequency-threshold curves of single auditory neurons whose most sensitive frequency was a 1/2 octave higher than the exposure frequency. The findings are consistent with the notion that dendritic swelling causes a non-selective decrease in sensitivity to all frequencies of sound.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cochlea / pathology*
  • Cochlear Nerve / physiopathology
  • Dendrites / pathology*
  • Dilatation, Pathologic
  • Guinea Pigs
  • Hair Cells, Auditory, Inner / pathology
  • Hearing Loss, Noise-Induced / pathology*
  • Hearing Loss, Noise-Induced / physiopathology
  • Neurons, Afferent / physiology
  • Spiral Ganglion / physiopathology