Contribution of aberrant GluK2-containing kainate receptors to chronic seizures in temporal lobe epilepsy

Cell Rep. 2014 Jul 24;8(2):347-54. doi: 10.1016/j.celrep.2014.06.032. Epub 2014 Jul 17.

Abstract

Kainate is a potent neurotoxin known to induce acute seizures. However, whether kainate receptors (KARs) play any role in the pathophysiology of temporal lobe epilepsy (TLE) is not known. In TLE, recurrent mossy fiber (rMF) axons form abnormal excitatory synapses onto other dentate granule cells that operate via KARs. The present study explores the pathophysiological implications of KARs in generating recurrent seizures in chronic epilepsy. In an in vitro model of TLE, seizure-like activity was minimized in mice lacking the GluK2 subunit, which is a main component of aberrant synaptic KARs at rMF synapses. In vivo, the frequency of interictal spikes and ictal discharges was strongly reduced in GluK2(-/-) mice or in the presence of a GluK2/GluK5 receptor antagonist. Our data show that aberrant GluK2-containing KARs play a major role in the chronic seizures that characterize TLE and thus constitute a promising antiepileptic target.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Epilepsy, Temporal Lobe / metabolism*
  • Epilepsy, Temporal Lobe / physiopathology
  • Excitatory Postsynaptic Potentials
  • Male
  • Mice
  • Mossy Fibers, Hippocampal / metabolism
  • Mossy Fibers, Hippocampal / physiology*
  • Receptors, Kainic Acid / antagonists & inhibitors
  • Receptors, Kainic Acid / genetics*
  • Receptors, Kainic Acid / metabolism
  • Seizures / metabolism*
  • Seizures / physiopathology

Substances

  • Gluk2 kainate receptor
  • Receptors, Kainic Acid