Display Settings:

Format

Send to:

Choose Destination
We are sorry, but NCBI web applications do not support your browser and may not function properly. More information
J Neurophysiol. 2008 Jun;99(6):2929-37. doi: 10.1152/jn.00066.2008. Epub 2008 Apr 16.

Nasal solitary chemoreceptor cell responses to bitter and trigeminal stimulants in vitro.

Author information

  • 1Rocky Mountain Taste and Smell Center, University of Colorado Denver School of Medicine, Aurora, CO 80045, USA. bgulbran@ucalgary.ca

Abstract

Nasal trigeminal chemosensitivity in mice and rats is mediated in part by epithelial solitary chemoreceptor (chemosensory) cells (SCCs), but the exact role of these cells in chemoreception is unclear. Histological evidence suggests that SCCs express elements of the bitter taste transduction pathway including T2R (bitter taste) receptors, the G protein alpha-gustducin, PLCbeta2, and TRPM5, leading to speculation that SCCs are the receptor cells that mediate trigeminal nerve responses to bitter taste receptor ligands. To test this hypothesis, we used calcium imaging to determine whether SCCs respond to classic bitter-tasting or trigeminal stimulants. SCCs from the anterior nasal cavity were isolated from transgenic mice in which green fluorescent protein (GFP) expression was driven by either TRPM5 or gustducin. Isolated cells were exposed to a variety of test stimuli to determine which substances caused an increase in intracellular Ca2+ ([Ca2+]i). GFP-positive cells respond with increased [Ca2+]i to the bitter receptor ligand denatonium and this response is blocked by the PLC inhibitor U73122. In addition, GFP+ cells respond to the neuromodulators adenosine 5'-triphosphate and acetylcholine but only very rarely to other bitter-tasting or trigeminal stimuli. Our results demonstrate that TRPM5- and gustducin-expressing nasal SCCs respond to the T2R agonist denatonium via a PLC-coupled transduction cascade typical of T2Rs in the taste system.

PMID:
18417634
[PubMed - indexed for MEDLINE]
PMCID:
PMC2765583
Free PMC Article

Images from this publication.See all images (6)Free text

Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6

Publication Types, MeSH Terms, Substances, Grant Support

Publication Types

MeSH Terms

Substances

Grant Support

PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk