Glutamate receptor channels in rat DRG neurons: activation by kainate and quisqualate and blockade of desensitization by Con A

Neuron. 1990 Sep;5(3):255-66. doi: 10.1016/0896-6273(90)90163-a.


Primary afferent C fibers in rat dorsal roots are depolarized by the excitatory amino acids kainate and domoate. Under whole-cell voltage clamp, kainate and domoate increase membrane conductance in a subpopulation of freshly dissociated DRG neurons. In contrast to kainate currents observed in CNS neurons, responses to kainate and domoate in DRG cells desensitize with prolonged agonist exposure. Half-maximal activation is achieved with much lower concentrations of kainate and domoate in sensory neurons than in CNS neurons from cerebral cortex. Rapid applications of glutamate, quisqualate, and AMPA evoke a transient current in DRG neurons and desensitize cells to subsequent applications of kainate or domoate. Brief incubation with the lectin concanavalin A eliminates desensitization to excitatory amino acids; after treatment with concanavalin A, all five agonists gate sustained currents of similar amplitude via the same receptor.

Publication types

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

MeSH terms

  • Amino Acids / pharmacology
  • Animals
  • Concanavalin A / pharmacology*
  • Dose-Response Relationship, Drug
  • Electrophysiology
  • Ganglia, Spinal / cytology
  • Ganglia, Spinal / metabolism*
  • Kainic Acid / analogs & derivatives
  • Kainic Acid / antagonists & inhibitors
  • Kainic Acid / pharmacology*
  • Neurons / metabolism*
  • Oxadiazoles / antagonists & inhibitors
  • Oxadiazoles / pharmacology*
  • Quisqualic Acid
  • Receptors, Glutamate
  • Receptors, Neurotransmitter / physiology*


  • Amino Acids
  • Oxadiazoles
  • Receptors, Glutamate
  • Receptors, Neurotransmitter
  • Concanavalin A
  • Quisqualic Acid
  • domoic acid
  • Kainic Acid