Patterns of innervation of outer hair cells in a chimpanzee: II. Efferent endings

Howard W. Francis, Joseph B. Nadol

Research output: Contribution to journalArticle


A morphometric analysis of the efferent innervation of the outer hair cells in the organ of Corti of one chimpanzee was performed. There was a wide variability in the size of efferent endings which ranged from approximately 0.1 to 4.5 μm3 in volume. Based on the size distribution of endings, a volume of 1.0 μm3 was chosen to divide efferent endings into two groups, 'large' and 'small'. The incidence of large efferent fibers decreased from base to apex and from the first to third row of each turn, whereas the incidence of small efferents increased from base to apex and from the first to third row in each turn. This data was interpreted to suggest that at least two types of efferent endings may exist at the base of outer hair cells of the organ of Corti in the chimpanzee.

Original languageEnglish (US)
Pages (from-to)217-221
Number of pages5
JournalHearing Research
Issue number2
Publication statusPublished - 1993
Externally publishedYes



  • Efferent innervation
  • Organ of Corti
  • Outer hair cell

ASJC Scopus subject areas

  • Sensory Systems

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