Synaptic code for sensory modalities revealed by C. elegans GLR-1 glutamate receptor

Nature. 1995 Nov 2;378(6552):82-5. doi: 10.1038/378082a0.


How does the nervous system encode environmental stimuli as sensory experiences? Both the type (visual, olfactory, gustatory, mechanical or auditory) and the quality of a stimulus (spatial position, intensity or frequency) are represented as a neural code. Here we undertake a genetic analysis of sensory modality coding in Caenorhabditis elegans. The ASH sensory neurons respond to two distinct sensory stimuli (nose touch and osmotic stimuli). A mutation in the glr-1 (glutamate receptor) gene eliminates the response to nose touch but not to osmotic repellents. The predicted GLR-1 protein is roughly 40% identical to mammalian AMPA-class glutamate receptor (GluR) subunits. Analysis of glr-1 expression and genetic mosaics indicates that GLR-1 receptors act in synaptic targets of the ASH neurons. We propose that discrimination between the ASH sensory modalities arises from differential release of ASH neurotransmitters in response to different stimuli.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Caenorhabditis elegans / genetics
  • Caenorhabditis elegans / physiology*
  • Caenorhabditis elegans Proteins*
  • Chimera
  • Gene Expression
  • Membrane Proteins / physiology*
  • Movement
  • Mutation
  • Nerve Tissue Proteins / physiology*
  • Neurons / physiology
  • Neurons, Afferent / physiology*
  • Receptors, AMPA
  • Receptors, Glutamate / genetics
  • Receptors, Glutamate / physiology*
  • Synapses / physiology*
  • Touch


  • Caenorhabditis elegans Proteins
  • Membrane Proteins
  • Nerve Tissue Proteins
  • Receptors, AMPA
  • Receptors, Glutamate
  • glr-1 protein, C elegans