Abstract
Receptor proteins for photoreception have been studied for several decades. More recently, putative receptors for olfaction have been isolated and characterized. In contrast, no receptors for taste have been identified yet by molecular cloning. This report describes experiments aimed at identifying a receptor responsible for the taste of monosodium glutamate (MSG). Using reverse transcriptase (RT)-PCR, we found that several ionotropic glutamate receptors are present in rat lingual tissues. However, these receptors also could be detected in lingual tissue devoid of taste buds. On the other hand, RT-PCR and RNase protection assays indicated that a G- protein-coupled metabotropic glutamate receptor, mGluR4, also is expressed in lingual tissues and is limited only to taste buds. In situ hybridization demonstrated that mGluR4 is detectable in 40-70% of vallate and foliate taste buds but not in surrounding nonsensory epithelium, confirming the localization of this metabotropic receptor to gustatory cells. Expression of mGluR4 in taste buds is higher in preweaning rats compared with adult rats. This may correspond to the known higher sensitivity to the taste of MSG in juvenile rodents. Finally, behavioral studies have indicated that MSG and L- 2-amino-4-phosphonobutyrate (L-AP4), a ligand for mGluR4, elicit similar tastes in rats. We conclude that mGluR4 may be a chemosensory receptor responsible, in part, for the taste of MSG.
| Original language | English |
|---|---|
| Pages (from-to) | 3817-3826 |
| Number of pages | 10 |
| Journal | Journal of Neuroscience |
| Volume | 16 |
| Issue number | 12 |
| State | Published - Jun 20 1996 |
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Keywords
- chemosensory
- glutamate receptors
- gustation
- rats
- taste buds
- umami
ASJC Scopus subject areas
- Neuroscience(all)
Cite this
The taste of monosodium glutamate : Membrane receptors in taste buds. / Chaudhari, Nirupa; Yang, Hui; Lamp, Cynthia; Delay, Eugene; Cartford, Claire; Than, Trang; Roper, Stephen D.
In: Journal of Neuroscience, Vol. 16, No. 12, 20.06.1996, p. 3817-3826.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - The taste of monosodium glutamate
T2 - Membrane receptors in taste buds
AU - Chaudhari, Nirupa
AU - Yang, Hui
AU - Lamp, Cynthia
AU - Delay, Eugene
AU - Cartford, Claire
AU - Than, Trang
AU - Roper, Stephen D
PY - 1996/6/20
Y1 - 1996/6/20
N2 - Receptor proteins for photoreception have been studied for several decades. More recently, putative receptors for olfaction have been isolated and characterized. In contrast, no receptors for taste have been identified yet by molecular cloning. This report describes experiments aimed at identifying a receptor responsible for the taste of monosodium glutamate (MSG). Using reverse transcriptase (RT)-PCR, we found that several ionotropic glutamate receptors are present in rat lingual tissues. However, these receptors also could be detected in lingual tissue devoid of taste buds. On the other hand, RT-PCR and RNase protection assays indicated that a G- protein-coupled metabotropic glutamate receptor, mGluR4, also is expressed in lingual tissues and is limited only to taste buds. In situ hybridization demonstrated that mGluR4 is detectable in 40-70% of vallate and foliate taste buds but not in surrounding nonsensory epithelium, confirming the localization of this metabotropic receptor to gustatory cells. Expression of mGluR4 in taste buds is higher in preweaning rats compared with adult rats. This may correspond to the known higher sensitivity to the taste of MSG in juvenile rodents. Finally, behavioral studies have indicated that MSG and L- 2-amino-4-phosphonobutyrate (L-AP4), a ligand for mGluR4, elicit similar tastes in rats. We conclude that mGluR4 may be a chemosensory receptor responsible, in part, for the taste of MSG.
AB - Receptor proteins for photoreception have been studied for several decades. More recently, putative receptors for olfaction have been isolated and characterized. In contrast, no receptors for taste have been identified yet by molecular cloning. This report describes experiments aimed at identifying a receptor responsible for the taste of monosodium glutamate (MSG). Using reverse transcriptase (RT)-PCR, we found that several ionotropic glutamate receptors are present in rat lingual tissues. However, these receptors also could be detected in lingual tissue devoid of taste buds. On the other hand, RT-PCR and RNase protection assays indicated that a G- protein-coupled metabotropic glutamate receptor, mGluR4, also is expressed in lingual tissues and is limited only to taste buds. In situ hybridization demonstrated that mGluR4 is detectable in 40-70% of vallate and foliate taste buds but not in surrounding nonsensory epithelium, confirming the localization of this metabotropic receptor to gustatory cells. Expression of mGluR4 in taste buds is higher in preweaning rats compared with adult rats. This may correspond to the known higher sensitivity to the taste of MSG in juvenile rodents. Finally, behavioral studies have indicated that MSG and L- 2-amino-4-phosphonobutyrate (L-AP4), a ligand for mGluR4, elicit similar tastes in rats. We conclude that mGluR4 may be a chemosensory receptor responsible, in part, for the taste of MSG.
KW - chemosensory
KW - glutamate receptors
KW - gustation
KW - rats
KW - taste buds
KW - umami
UR - http://www.scopus.com/inward/record.url?scp=0030006520&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0030006520&partnerID=8YFLogxK
M3 - Article
C2 - 8656276
AN - SCOPUS:0030006520
VL - 16
SP - 3817
EP - 3826
JO - Journal of Neuroscience
JF - Journal of Neuroscience
SN - 0270-6474
IS - 12
ER -