Expression of metabotropic glutamate receptor group I in rat gustatory papillae

Takashi Toyono, Yuji Seta, Shinji Kataoka, Shintaro Kawano, Ryuichi Shigemoto, Kuniaki Toyoshima

Research output: Contribution to journalArticlepeer-review

94 Citations (Scopus)


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 chain reaction (RT-PCR), in situ hybridization, immunohistochemistry and immunoelectron microscopy. RT-PCR assay showed that mGluR1α and mGluR1β mRNAs were expressed in circumvallate papillae, but mGluR5 mRNA was not expressed. The positive signals of mGluR1 mRNA were detected only in circumvallate taste buds by in situ hybridization analysis. In cryosections of fungiform, foliate and circumvallate papillae, the antibody against mGluRla gave intense labeling on the taste hairs in all taste pores examined. In the developing taste buds, the positive signals of mGluR1α in taste hairs gradually increased with the increase in number of taste bud cells. These results show that, in addition to taste-mGluR4 and the heteromer of T1R1 and T1R3, mGluR1α may function as a receptor for glutamate (umami) taste sensation.

Original languageEnglish
Pages (from-to)29-35
Number of pages7
JournalCell and tissue research
Issue number1
Publication statusPublished - Jul 1 2003

All Science Journal Classification (ASJC) codes

  • Pathology and Forensic Medicine
  • Histology
  • Cell Biology


Dive into the research topics of 'Expression of metabotropic glutamate receptor group I in rat gustatory papillae'. Together they form a unique fingerprint.

Cite this