Evidence against a role for metabotropic glutamate receptors in mossy fiber LTP: the use of mutant mice and pharmacological antagonists

A. Y. Hsia, P. A. Salin, P. E. Castillo, A. Aiba, A. Abeliovich, S. Tonegawa, R. A. Nicoll

Research output: Contribution to journalArticle

41 Scopus citations


We have used a number of approaches to address a possible role of metabotropic glutamate receptors (mGluRs) in mossy fiber long-term potentiation (LTP) in the hippocampus. We have used two types of mutant mice-one lacking the mGluR1 subtype of receptor and one lacking the gamma isoform of protein kinase C. In neither type of mouse did we find any alteration in the magnitude of mossy fiber LTP. We next examined whether mGluRs might modulate the magnitude and/or threshold for the induction of mossy fiber LTP. In these experiments we used tetani that were either just subthreshold or just suprathreshold for generating LTP. The mGluR antagonist (+)-α-methyl-4-carboxyphenylglycine [(+)MCPG] did not convert a subthreshold tetanus into a suprathreshold tetanus, nor did (+)MCPG have any effect on the small amount of LTP that was generated by a just suprathreshold tetanus. Based on our studies, we have been unable to identify a role for mGluRs in mossy fiber LTP.

Original languageEnglish (US)
Pages (from-to)1567-1572
Number of pages6
Issue number11
StatePublished - Nov 1995
Externally publishedYes



  • Long-term potentiation (LTP)
  • hippocampus
  • metabotropic glutamate receptors (mGluRs)
  • mossy fibers
  • protein kinase C

ASJC Scopus subject areas

  • Pharmacology
  • Cellular and Molecular Neuroscience

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