Elevated extracellular levels of glutamate, aspartate and gamma-aminobutyric acid within the intraoperative, spontaneously epileptiform human hippocampus

Epilepsy Res. 2003 Apr;54(1):73-9. doi: 10.1016/s0920-1211(03)00035-4.


We report preliminary results from four patients subjected to hippocampal electrocorticography and microdialysis during temporal lobe epilepsy surgery. In two cases, spontaneously vigorous hippocampal epileptiform activity (EA) was identified; basal dialysate levels for hippocampal glutamate, aspartate, and gamma-aminobutyric acid ranged from approximately 23- to 84-fold, 19- to 33-fold and 10- to 34-fold higher, respectively, compared to the two cases of minimal hippocampal EA. These findings represent the first intraoperative evidence of elevated extracellular levels of neuroactive amino acids within the spontaneously epileptiform human hippocampus.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Anesthesia, General
  • Aspartic Acid / metabolism*
  • Electroencephalography
  • Epilepsy, Temporal Lobe / metabolism*
  • Epilepsy, Temporal Lobe / surgery*
  • Female
  • Glutamic Acid / metabolism*
  • Hippocampus / metabolism*
  • Hippocampus / surgery*
  • Humans
  • Intraoperative Period
  • Male
  • gamma-Aminobutyric Acid / metabolism*


  • Aspartic Acid
  • Glutamic Acid
  • gamma-Aminobutyric Acid