Subunit composition of kainate receptors in hippocampal interneurons

Neuron. 2000 Nov;28(2):475-84. doi: 10.1016/s0896-6273(00)00126-4.

Abstract

Kainate receptor activation affects GABAergic inhibition in the hippocampus by mechanisms that are thought to involve the GluR5 subunit. We report that disruption of the GluR5 subunit gene does not cause the loss of functional KARs in CA1 interneurons, nor does it prevent kainate-induced inhibition of evoked GABAergic synaptic transmission onto CA1 pyramidal cells. However, KAR function is abolished in mice lacking both GluR5 and GluR6 subunits, indicating that KARs in CA1 stratum radiatum interneurons are heteromeric receptors composed of both subunits. In addition, we show the presence of presynaptic KARs comprising the GluR6 but not the GluR5 subunit that modulate synaptic transmission between inhibitory interneurons. The existence of two separate populations of KARs in hippocampal interneurons adds to the complexity of KAR localization and function.

Publication types

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

MeSH terms

  • Animals
  • Cells, Cultured
  • Crosses, Genetic
  • Dose-Response Relationship, Drug
  • Down-Regulation / drug effects
  • Excitatory Amino Acid Antagonists
  • Hippocampus / cytology
  • Hippocampus / drug effects
  • Hippocampus / metabolism*
  • Interneurons / cytology
  • Interneurons / drug effects
  • Interneurons / metabolism*
  • Kainic Acid / metabolism
  • Kainic Acid / pharmacology
  • Mice
  • Mice, Inbred Strains
  • Mice, Knockout
  • Neural Inhibition / drug effects
  • Neural Inhibition / physiology
  • Neuromuscular Depolarizing Agents / pharmacology
  • Neurons, Afferent / drug effects
  • Neurons, Afferent / metabolism
  • Patch-Clamp Techniques
  • Protein Subunits*
  • Pyramidal Cells / cytology
  • Pyramidal Cells / drug effects
  • Pyramidal Cells / metabolism
  • Receptors, AMPA / antagonists & inhibitors
  • Receptors, Kainic Acid / deficiency
  • Receptors, Kainic Acid / genetics
  • Receptors, Kainic Acid / metabolism*
  • Synaptic Transmission / drug effects
  • Synaptic Transmission / physiology
  • Tetrodotoxin / pharmacology
  • gamma-Aminobutyric Acid / metabolism

Substances

  • Excitatory Amino Acid Antagonists
  • Gluk1 kainate receptor
  • Gluk2 kainate receptor
  • Neuromuscular Depolarizing Agents
  • Protein Subunits
  • Receptors, AMPA
  • Receptors, Kainic Acid
  • Tetrodotoxin
  • gamma-Aminobutyric Acid
  • Kainic Acid