Decreased cortical levels of astrocytic glutamate transport protein GLT-1 in a rat model of posttraumatic epilepsy

Neurosci Lett. 2000 Aug 11;289(3):185-8. doi: 10.1016/s0304-3940(00)01284-2.

Abstract

The extracellular homeostasis of glutamate in the brain is maintained by the efficient uptake into astroglial cells. The high extracellular glutamate levels seen during seizures are therefore probably a result of both an increased synaptic release and a deranged glutamate uptake. In this study we used immuno-blotting technique to measure the cortical levels of the astrocytic glutamate transport protein (GLT-1) and of the glutamate and aspartate transporting protein (GLAST) in an epilepsy model induced by ferrous chloride injection in the cortex of rats. The levels of GLT-1 were lower in epileptic rats than in controls, day 1 and 5 after induction, but not at 3 months. Glial fibrillary protein (GFAP) levels increased with time in the epileptic model, whereas GLAST and beta-tubulin III remained unchanged compared to controls. The results suggest that the transient decrease of GLT-1 could play a role in epileptogenesis, while recurrent seizure activity may be maintained by other mechanisms.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATP-Binding Cassette Transporters / metabolism*
  • Amino Acid Transport System X-AG
  • Animals
  • Astrocytes / drug effects
  • Astrocytes / metabolism*
  • Astrocytes / pathology
  • Cerebral Cortex / metabolism*
  • Cerebral Cortex / pathology
  • Cerebral Cortex / physiopathology
  • Disease Models, Animal
  • Electroencephalography / drug effects
  • Epilepsy, Post-Traumatic / chemically induced
  • Epilepsy, Post-Traumatic / metabolism*
  • Epilepsy, Post-Traumatic / physiopathology
  • Ferrous Compounds / adverse effects
  • Glial Fibrillary Acidic Protein / metabolism
  • Glutamic Acid / metabolism*
  • Male
  • Neurons / drug effects
  • Neurons / metabolism
  • Neurons / pathology
  • Rats
  • Rats, Sprague-Dawley
  • Tubulin / metabolism

Substances

  • ATP-Binding Cassette Transporters
  • Amino Acid Transport System X-AG
  • Ferrous Compounds
  • Glial Fibrillary Acidic Protein
  • Tubulin
  • Glutamic Acid
  • ferrous chloride