Alterations in glutamate transporter protein levels in kindling-induced epilepsy

J Neurochem. 1997 Apr;68(4):1564-70. doi: 10.1046/j.1471-4159.1997.68041564.x.

Abstract

There is increasing evidence that levels of glutamate are elevated in certain brain regions immediately prior to and during induction and propagation of seizures. Modulation of high-affinity glutamate uptake is a potential mechanism responsible for the elevated levels observed with Seizures. To date, three distinct Na(+)-dependent glutamate transporters have been cloned from rat and rabbit: GLT-1, GLAST, and EAAC-1. We performed a series of experiments to determine whether levels of these transporters are altered in amygdala-kindled rats. Levels of GLT-1, GLAST, and EAAC-1 were examined in three brain regions (hippocampus, piriform cortex/amygdala, and limbic forebrain) by quantitative immunoblotting using subtype-specific antibodies. GLAST protein was down-regulated in the piriform cortex/amygdala region of kindled rats as early as 24 h after one stage 3 seizure and persisting through multiple stage 5 seizures. In contrast, kindling induced an increase in EAAC-1 levels in piriform cortex/amygdala and hippocampus once the animals had reached the stage 5 level. NO changes in GLT-1 were observed in any region examined. Changes in transporter levels could contribute to the changes in glutamate levels seen with kindling.

Publication types

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

MeSH terms

  • ATP-Binding Cassette Transporters / analysis
  • ATP-Binding Cassette Transporters / metabolism*
  • Amino Acid Transport System X-AG
  • Animals
  • Biological Transport / physiology
  • Blotting, Western
  • Brain Chemistry / physiology
  • Cerebral Cortex / chemistry
  • Cerebral Cortex / physiopathology
  • Epilepsy / etiology
  • Epilepsy / metabolism*
  • Glucose Transporter Type 1
  • Hippocampus / chemistry
  • Hippocampus / physiopathology
  • Kindling, Neurologic / physiology*
  • Male
  • Monosaccharide Transport Proteins / analysis
  • Monosaccharide Transport Proteins / metabolism*
  • Rabbits
  • Rats
  • Rats, Sprague-Dawley

Substances

  • ATP-Binding Cassette Transporters
  • Amino Acid Transport System X-AG
  • Glucose Transporter Type 1
  • Monosaccharide Transport Proteins