Anatomical and physiological development of the human inner ear

Hear Res. 2016 Aug;338:9-21. doi: 10.1016/j.heares.2016.02.004. Epub 2016 Feb 18.

Abstract

We describe the development of the human inner ear with the invagination of the otic vesicle at 4 weeks gestation (WG), the growth of the semicircular canals from 5 WG, and the elongation and coiling of the cochlea at 10 WG. As the membranous labyrinth takes shape, there is a concomitant development of the sensory neuroepithelia and their associated structures within. This review details the growth and differentiation of the vestibular and auditory neuroepithelia, including synaptogenesis, the expression of stereocilia and kinocilia, and innervation of hair cells by afferent and efferent nerve fibres. Along with development of essential sensory structures we outline the formation of crucial accessory structures of the vestibular system - the cupula and otolithic membrane and otoconia as well as the three cochlea compartments and the tectorial membrane. Recent molecular studies have elaborated on classical anatomical studies to characterize the development of prosensory and sensory regions of the fetal human cochlea using the transcription factors, PAX2, MAF-B, SOX2, and SOX9. Further advances are being made with recent physiological studies that are beginning to describe when hair cells become functionally active during human gestation. This article is part of a Special Issue entitled <Annual Reviews 2016>.

Publication types

  • Review
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Differentiation
  • Cell Lineage
  • Cochlea / embryology
  • Ear, Inner / embryology*
  • Hair Cells, Auditory / physiology*
  • Humans
  • Mice
  • Neurons / metabolism
  • Organ of Corti / embryology
  • Otolithic Membrane / embryology
  • PAX2 Transcription Factor / metabolism
  • Regeneration
  • SOX9 Transcription Factor / metabolism
  • SOXB1 Transcription Factors / metabolism
  • Semicircular Canals / embryology
  • Synapses / metabolism
  • Time Factors
  • Transcription Factors / metabolism
  • Vestibule, Labyrinth / embryology*
  • Vestibule, Labyrinth / metabolism

Substances

  • PAX2 Transcription Factor
  • PAX2 protein, human
  • SOX2 protein, human
  • SOX9 Transcription Factor
  • SOX9 protein, human
  • SOXB1 Transcription Factors
  • Transcription Factors