Expression of metabotropic glutamate receptor group I in rat gustatory papillae

@article{Toyono2003ExpressionOM,
  title={Expression of metabotropic glutamate receptor group I in rat gustatory papillae},
  author={Takashi Toyono and Yuji Seta and Shinji Kataoka and Shintaro Kawano and Ryuichi Shigemoto and Kuniaki Toyoshima},
  journal={Cell and Tissue Research},
  year={2003},
  volume={313},
  pages={29-35}
}
Abstract.Taste-metabotropic glutamate receptor 4 (taste-mGluR4) and the heteromers of T1R1 and T1R3 are candidate receptors involved in the sense of umami (monosodium glutamate) taste. Although the expression of group III mGluRs (taste-mGluR4) has been demonstrated in taste tissues, no mention has been made of the expression of group I mGluRs (mGluR1 and mGluR5) in taste tissues. We examined the expression of mGluR1 and mGluR5 in rat gustatory tissues by using reverse transcription-polymerase… 
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References

SHOWING 1-10 OF 41 REFERENCES
Expression of the metabotropic glutamate receptor, mGluR4a, in the taste hairs of taste buds in rat gustatory papillae.
TLDR
The results of the present study strongly suggest that brain-mGluR4 may function even more importantly than the former as a receptor for glutamate, i.e. the umami taste sensation.
The Taste of Monosodium Glutamate: Membrane Receptors in Taste Buds
TLDR
It is concluded that mGluR4 may be a chemosensory receptor responsible, in part, for the taste of MSG.
Molecular and Physiological Evidence for Glutamate (Umami) Taste Transduction via a G Protein‐Coupled Receptor a
TLDR
Experiments on mice with the mGluR4 gene knocked out support the interpretation that mGLUR4 is a key component in glutamate taste, and speculate upon the significance of two glutamate receptor pathways in taste buds.
Physiological evidence for ionotropic and metabotropic glutamate receptors in rat taste cells.
TLDR
The results suggest that NMDA-like receptors and at least two types of group III mGluRs are present in taste receptor cells, and these may be coactivated by MSG.
In Situ Ca2+ Imaging Reveals Neurotransmitter Receptors for Glutamate in Taste Receptor Cells
TLDR
A new calcium-imaging technique for taste buds was reported that allowed us to test for the presence of glutamate receptors (GluRs) in living isolated tissue preparations, suggesting that glutamate is a neurotransmitter there.
Responses to umami substances in taste bud cells innervated by the chorda tympani and glossopharyngeal nerves.
TLDR
Calcium imaging studies demonstrate that some mouse taste cells isolated from the fungiform papilla innervated by the CT respond selectively to MSG and/or IMP or GMP, and gurmarin-insensitive components of receptors for US may be commonly involved in transduction for umami taste in taste cells on both anterior and posterior parts of the tongue.
A Plethora of Taste Receptors
Distribution of the mRNA for a metabotropic glutamate receptor (mGluR1) in the central nervous system: An in situ hybridization study in adult and developing rat
TLDR
In the developing rat brain, the level of mGluR1 expression gradually increased during early postnatal days in accordance with the maturation of neuronal elements.
Physiological studies on umami taste.
TLDR
It was proposed that the umami taste is a fifth basic taste, and that there is a unique receptor for umami substances, and the taste of agonists for brain glutamate receptors was compared.
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