Role of a metabotropic glutamate receptor in synaptic modulation in the accessory olfactory bulb

Nature. 1993 Dec 16;366(6456):687-90. doi: 10.1038/366687a0.


Various functions of glutamate transmission are mediated by both ionotropic and metabotropic glutamate receptors. The metabotropic glutamate receptors (mGluRs) consists of at least six different subtypes that are classified into three subgroups, mGluR1/mGluR5, mGluR2/mGluR3, and mGluR4/mGluR6 (refs 1-5), but their physiological roles are largely unknown. Here we report the identification of a very potent agonist for mGluR2/mGluR3, DCG-IV, and the specific localization of mGluR2 in granule cell dendrites that form dendrodendritic synapses with mitral cells in the accessory olfactory bulb. Using the DCG-IV agonist for mGluR2 in combination with slice patch-recording, we demonstrate that the granule cell mGluR2 presynaptically suppresses inhibitory GABA (gamma-aminobutyrate) transmission to the mitral cell. Our results indicate that mGluR2 in granule cells plays an important role in the persistent excitation of olfactory sensory transmission in the accessory olfactory bulb by relieving mitral cells from the GABA inhibition.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CHO Cells
  • Cricetinae
  • Cyclopropanes / pharmacology
  • Dendrites / physiology
  • Glutamates / metabolism
  • Glutamic Acid
  • Glycine / analogs & derivatives
  • Glycine / pharmacology
  • In Vitro Techniques
  • Interneurons / physiology
  • Olfactory Bulb / cytology
  • Olfactory Bulb / physiology*
  • Rats
  • Receptors, Glutamate / drug effects
  • Receptors, Glutamate / physiology*
  • Receptors, N-Methyl-D-Aspartate / drug effects
  • Synaptic Transmission / drug effects
  • Synaptic Transmission / physiology*
  • gamma-Aminobutyric Acid / metabolism
  • gamma-Aminobutyric Acid / physiology


  • Cyclopropanes
  • Glutamates
  • Receptors, Glutamate
  • Receptors, N-Methyl-D-Aspartate
  • 2-(2,3-dicarboxycyclopropyl)glycine
  • Glutamic Acid
  • gamma-Aminobutyric Acid
  • Glycine