Archives of oto-rhino-laryngology

, Volume 237, Issue 3, pp 201–208 | Cite as

Degeneration of cochlear neurons after amikacin intoxication in the rat

  • E. Bichler
  • H. Spoendlin
  • H. Rauchegger


Intoxication with high doses of the aminoglycoside antibiotic amikacin in a supranormal sensitive period in the rat induces complete destruction of the inner and outer hair cells in the organ of Corti in all turns, whereas the supporting cells remain partially preserved in the upper turns. With increasing survival time, the number of ganglion cells in the spiral ganglion decreases progressively, reaching a minimum of about 10% surviving cells after 12 months. Both type I and type II neurons are subject to retrograde degeneration, although type-II cells degenerate more slowly than type-I cells. The presence or absence of supporting cells in the organ of Corti does not seem to influence neuronal degeneration. This retrograde degeneration is similar in all animals so far studied but its time course is different for different species. Retrograde degeneration after destruction of Corti's organ is a long-lasting process and is never completed at once. This must be taken into consideration in the treatment of total deafness with electric stimulation of surviving neurons.

Key words

Amikacin intoxication Cochlea Spiral ganglion Neuronal degeneration Rat 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Bredberg G (1968) Cellular pattern and nerve supply of the human organ of Corti. Acta Otolaryngol [Suppl] (Stockh) 236: 1–135Google Scholar
  2. Carlier E, Pujol R (1980) Supra-normal sensitivity to ototoxic antibiotic of the developing rat cochlea. Arch Otorhinolaryngol 226: 129–133Google Scholar
  3. Johnsson LG (1974) Sequence of degeneration of corti's organ and its first-order neuron. Ann Otol 83: 294–303Google Scholar
  4. Kellerhals B, Engström H, Ades HW (1967) Die Morphologie der Ganglionspirale cochlea. Acta Otolaryngol [Suppl] (Stockh), 226: 1–78Google Scholar
  5. Kiang NYS, Rho IM, Northrop CC, Liberman MC, Ryngo DK (1982) Hair cell innervation by spiral ganglion cells in adult cats. Science 217: 175–177Google Scholar
  6. Otte J, Schuhknecht HF, Kerr AG (1978) Ganglion cell populations in normal and pathological human cochleae. Implications for cochlear implants. Laryngoscope 88: 1231–1246Google Scholar
  7. Rosenbluth J (1962) The fine structure of acoustic ganglia in the rat. J Cell Biol 12: 329–359Google Scholar
  8. Santi PA, Ruggero MA, Nelson DA, Turner CW (1982) Kanamycin and bumetanide ototoxicity: anatomical, physiological and behavioral correlates. Hear Res 7: 261–279Google Scholar
  9. Schuknecht HF (1974) Pathology of the ear, chapter 9. Harvard University Press, Cambridge, Massachusetts, pp 333–350Google Scholar
  10. Spoendlin H, Babel J, Bischoff A (1970) Ultrastructure of the peripheral nervous system and sense organ. In: Babel I, Bischoff A, Spoendlin H (eds) Atlas of normal and pathological anatomy, vol 8. Thieme, Stuttgart, pp 1–452Google Scholar
  11. Spoendlin H (1971) Degeneration behaviour of the cochlear nerve. Arch Klin Exp Ohren-Nasen-Kehlkopfheilkd 200: 275–291Google Scholar
  12. Spoendlin H, Brun JB (1974) The block surface technique for evaluation of cochlear pathology. Arch Otorhinolaryngol 208: 145Google Scholar
  13. Spoendlin H (1979) Neural connections of the outer hair cell system. Acta Otolaryngol 87: 381–387Google Scholar
  14. Spoendlin H (1979) Anatomisch-pathologische Aspekte der Elektrostimulation des ertaubten Innenohres. Arch Otorhinolaryngol 223: 1–75Google Scholar
  15. Spoendlin H (1981) Differentiation of cochlear afferent neurons. Acta Otolarnygol (Stockh) 91: 451–456Google Scholar
  16. Spoendlin H (1982) The innervation of the outer hair cell system. Am J Otol 3: 274–278Google Scholar
  17. Tange RA, Huizing EH (1980) Hearing loss and inner ear changes in a patient suffering from severe gentamicin ototoxicity. Arch Otorhinolaryngol 228: 113–121Google Scholar
  18. Terayama Y, Kaneko Y, Kawamoto K, Sakai N (1977) Ultrastrutural changes of the nerve elements following disruption of the organ of Corti. I. Nerve elements in the organ of Corti. Acta Otolaryngol 83: 291–302Google Scholar
  19. Theopold HM (1977) Comparative surface studies of ototoxic effects of various aminoglycoside antibiotics on the organ of Corti in the guinea pig. Acta Otolaryngol 84: 57–64Google Scholar
  20. Walsh SM, Leake-Jones PA (1982) Chronic electrical stimulation of auditory nerve in cat: physiological and histological results. Hear Res 7: 281–304Google Scholar
  21. Wersäll J (1980) The ototoxic potential of netilmicin compared with amikacin. Scand J Infec Dis [Suppl] 23: 104–113Google Scholar

Copyright information

© Springer-Verlag 1983

Authors and Affiliations

  • E. Bichler
    • 1
  • H. Spoendlin
    • 1
  • H. Rauchegger
    • 1
  1. 1.ENT-Department of the University of InnsbruckInnsbruckAustria

Personalised recommendations