Age-related primary cochlear neuronal degeneration in human temporal bones

Chadi A. Makary, Jennifer Shin, Sharon G. Kujawa, M. Charles Liberman, Saumil N. Merchant

Research output: Contribution to journalArticle

Abstract

In cases of acquired sensorineural hearing loss, death of cochlear neurons is thought to arise largely as a result of sensory-cell loss. However, recent studies of acoustic overexposure report massive degeneration of the cochlear nerve despite complete hair cell survival (Kujawa and Liberman, J Neurosci 29:14077-14085, 2009). To assess the primary loss of spiral ganglion cells (SGCs) in human ears, neuronal counts were performed in 100 temporal bones from 100 individuals, aged newborn to 100 years, selected to include only cases with a normal population of inner and outer hair cells. Ganglion cell counts declined at a mean rate of 100 cells per year of life. There were no significant gender or inter-aural differences, and a slight increase in degeneration in the basal turn re upper turns was not statistically significant. The agerelated decline in SGCs was significantly less than that in prior studies that included ears with hair cell loss (Otte et al., Laryngoscope 88:1231-1246, 1978), but significantly more than for analogous data on vestibular ganglion cells in cases without vestibular hair cell loss (Velazquez-Villasenor et al., Ann Otol Rhinol Laryngol Suppl 181:14-19, 2000). The age-related decline in SGC counts may contribute to the wellknown decline in hearing-in-noise performance, and the data will help in interpretation of histopathological findings from temporal bones with known otologic disease.

Original languageEnglish (US)
Pages (from-to)711-717
Number of pages7
JournalJARO - Journal of the Association for Research in Otolaryngology
Volume12
Issue number6
DOIs
StatePublished - Dec 1 2011
Externally publishedYes

Fingerprint

Temporal Bone
Cochlea
Spiral Ganglion
Ear
Alopecia
Outer Auditory Hair Cells
Inner Auditory Hair Cells
Ganglia
Cell Count
Vestibular Hair Cells
Ear Diseases
Laryngoscopes
Cochlear Nerve
Sensorineural Hearing Loss
Acoustics
Hearing
Noise
Cell Survival
Neurons
Population

Keywords

  • Cochlear neurons
  • Histopathology
  • Otopathology
  • Spiral ganglion

ASJC Scopus subject areas

  • Otorhinolaryngology
  • Sensory Systems

Cite this

Age-related primary cochlear neuronal degeneration in human temporal bones. / Makary, Chadi A.; Shin, Jennifer; Kujawa, Sharon G.; Liberman, M. Charles; Merchant, Saumil N.

In: JARO - Journal of the Association for Research in Otolaryngology, Vol. 12, No. 6, 01.12.2011, p. 711-717.

Research output: Contribution to journalArticle

Makary, Chadi A. ; Shin, Jennifer ; Kujawa, Sharon G. ; Liberman, M. Charles ; Merchant, Saumil N. / Age-related primary cochlear neuronal degeneration in human temporal bones. In: JARO - Journal of the Association for Research in Otolaryngology. 2011 ; Vol. 12, No. 6. pp. 711-717.
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