Expression of alpha 4 and beta 2 nicotinic acetylcholine receptor subunit mRNA and localization of alpha-bungarotoxin binding proteins in the rat vestibular periphery

Cell Biol Int. 1995 Apr;19(4):291-300. doi: 10.1006/cbir.1995.1071.


In situ hybridization histochemistry was used to map the distribution of alpha 2, alpha 3, alpha 4, and beta 2 nAChR subunit mRNAs throughout the peripheral vestibular system of the rat. The alpha 4 and beta 2 nAChR subunit genes were co-expressed by populations of primary afferent neurons within Scarpa's ganglion, while there was no expression of the alpha 2, alpha 3, alpha 4, or beta 2 nAChR subunit genes by type I or type II vestibular hair cells. alpha-bungarotoxin binding to nAChRs in the vestibular end-organs was primarily limited to the afferent chalices surrounding type I hair cells and the basal aspect of type II hair cells. These data suggest that nAChRs composed of alpha 4 and beta 2 subunits are localized on afferent chalices innervating the type I vestibular hair cells and that the direct cholinergic efferent innervation of the type II vestibular hair cells utilizes nAChR composed of other subunits.

Publication types

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

MeSH terms

  • Afferent Pathways / metabolism
  • Animals
  • Bungarotoxins / metabolism*
  • Gene Expression
  • In Situ Hybridization
  • Male
  • RNA, Messenger / analysis*
  • Rats
  • Rats, Inbred Strains
  • Receptors, Nicotinic / genetics*
  • Receptors, Nicotinic / metabolism
  • Receptors, Nicotinic / ultrastructure
  • Vestibule, Labyrinth / chemistry*


  • Bungarotoxins
  • RNA, Messenger
  • Receptors, Nicotinic