Distinct physiological roles of the Gq-coupled metabotropic glutamate receptors Co-expressed in the same neuronal populations

J Cell Physiol. 2002 May;191(2):125-37. doi: 10.1002/jcp.10081.


The group I metabotropic glutamate receptors, mGluR1 and mGluR5, exhibit a high degree of sequence homology, and are often found co-expressed in the same neuronal populations. These receptors couple to a broad array of effector systems, and are implicated in diverse physiological and pathophysiological functions. Due to the high degree of sequence homology, and the findings that these receptors couple identically in recombinant systems, it has been generally assumed that these two group I mGluR subtypes would exhibit redundant function when coexpressed in the same neurons. With the advent of subtype-selective pharmacological tools, it has become possible to tease apart the functions of mGluR1 and mGluR5 in the same neuron. The emerging picture is one of diverse function, which implies differential regulation. Interestingly, the group I mGluRs are modulated by a rich variety of regulatory systems, which may explain how these receptors can mediate divergent actions when present in the same cell.

Publication types

  • Review

MeSH terms

  • Animals
  • Brain / cytology
  • Brain / metabolism*
  • Carrier Proteins / metabolism
  • GTP-Binding Protein alpha Subunits, Gq-G11
  • Glutamic Acid / analogs & derivatives
  • Glutamic Acid / metabolism*
  • Heterotrimeric GTP-Binding Proteins / metabolism*
  • Homer Scaffolding Proteins
  • Humans
  • Neurons / cytology
  • Neurons / metabolism*
  • Neuropeptides / metabolism
  • Receptors, Metabotropic Glutamate / drug effects
  • Receptors, Metabotropic Glutamate / metabolism*
  • Signal Transduction / physiology*
  • Synaptic Transmission / physiology*


  • Carrier Proteins
  • Homer Scaffolding Proteins
  • Neuropeptides
  • Receptors, Metabotropic Glutamate
  • Glutamic Acid
  • GTP-Binding Protein alpha Subunits, Gq-G11
  • Heterotrimeric GTP-Binding Proteins