New insights into regulation and function of planar polarity in the inner ear

Neurosci Lett. 2019 Sep 14;709:134373. doi: 10.1016/j.neulet.2019.134373. Epub 2019 Jul 8.


Acquisition of cell polarity generates signaling and cytoskeletal asymmetry and thus underpins polarized cell behaviors during tissue morphogenesis. In epithelial tissues, both apical-basal polarity and planar polarity, which refers to cell polarization along an axis orthogonal to the apical-basal axis, are essential for epithelial morphogenesis and function. A prime example of epithelial planar polarity can be found in the auditory sensory epithelium (or organ of Corti, OC). Sensory hair cells, the sound receptors, acquire a planar polarized apical cytoskeleton which is uniformely oriented along an axis orthogonal to the longitudinal axis of the cochlear duct. Both cell-intrinsic and tissue-level planar polarity are necessary for proper perception of sound. Here we review recent insights into the novel roles and mechanisms of planar polarity signaling gained from genetic analysis in mice, focusing mainly on the OC but also with some discussions on the vestibular sensory epithelia.

Keywords: Cochlea; Deafness; Hair bundle; Hair cell; Kinocilium; Planar cell polarity; Stereocilia.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Animals
  • Cell Polarity / physiology*
  • Ear, Inner
  • Hair Cells, Auditory / physiology
  • Hair Cells, Auditory, Inner / physiology*
  • Humans
  • Organ of Corti / cytology
  • Organ of Corti / physiology*
  • Stereocilia / physiology*