Histochemistry and Cell Biology

, Volume 137, Issue 4, pp 483–497

Cholinergic chemosensory cells in the auditory tube

  • G. Krasteva
  • P. Hartmann
  • T. Papadakis
  • M. Bodenbenner
  • L. Wessels
  • E. Weihe
  • B. Schütz
  • A. C. Langheinrich
  • V. Chubanov
  • T. Gudermann
  • I. Ibanez-Tallon
  • W. Kummer
Original Paper

DOI: 10.1007/s00418-012-0911-x

Cite this article as:
Krasteva, G., Hartmann, P., Papadakis, T. et al. Histochem Cell Biol (2012) 137: 483. doi:10.1007/s00418-012-0911-x

Abstract

The luminal composition of the auditory tube influences its function. The mechanisms involved in the monitoring are currently not known. For the lower respiratory epithelium, such a sentinel role is carried out by cholinergic brush cells. Here, using two different mouse strains expressing eGFP under the control of the promoter of choline acetyltransferase (ChAT), we show the presence of solitary cholinergic villin-positive brush cells also in the mouse auditory tube epithelium. They express the vesicular acetylcholine (ACh) transporter and proteins of the taste transduction pathway such as α-gustducin, phospholipase C beta 2 (PLCβ2) and transient receptor potential cation channel subfamily M member 5 (TRPM5). Immunoreactivity for TRPM5 and PLCβ2 was found regularly, whereas α-gustducin was absent in approximately 15% of the brush cells. Messenger RNA for the umami taste receptors (TasR), Tas1R1 and 3, and for the bitter receptors, Tas2R105 and Tas2R108, involved in perception of cycloheximide and denatonium were detected in the auditory tube. Using a transgenic mouse that expresses eGFP under the promotor of the nicotinic ACh receptor α3-subunit, we identified cholinoceptive nerve fibers that establish direct contacts to brush cells in the auditory tube. A subpopulation of these fibers displayed also CGRP immunoreactivity. Collectively, we show for the first time the presence of brush cells in the auditory tube. These cells are equipped with all proteins essential for sensing the composition of the luminal microenvironment and for communication of the changes to the CNS via attached sensory nerve fibers.

Keywords

Brush cell Chemosensory Cholinergic Sensory Taste Auditory tube Nicotinic 

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • G. Krasteva
    • 1
  • P. Hartmann
    • 1
  • T. Papadakis
    • 1
  • M. Bodenbenner
    • 1
  • L. Wessels
    • 1
  • E. Weihe
    • 2
  • B. Schütz
    • 2
  • A. C. Langheinrich
    • 3
  • V. Chubanov
    • 4
  • T. Gudermann
    • 4
  • I. Ibanez-Tallon
    • 4
  • W. Kummer
    • 1
  1. 1.Institute of Anatomy and Cell Biology, ECCPS, UGMLC, Justus-Liebig-UniversityGiessenGermany
  2. 2.Institute for Anatomy and Cell Biology, Philipps-University MarburgMarburgGermany
  3. 3.Department of RadiologyJustus-Liebig-University GiessenGiessenGermany
  4. 4.Walter-Straub-Institute for Pharmacology and ToxicologyLudwig-Maximilian-University MunichMunichGermany