Kynurenic acid inhibits synaptic and acidic amino acid-induced responses in the rat hippocampus and spinal cord

Brain Res. 1983 Aug 22;273(1):170-4. doi: 10.1016/0006-8993(83)91108-3.


Kynurenic acid, a tryptophan metabolite, inhibits excitatory synaptic transmission in the rat hippocampal slice and the isolated immature rat spinal cord, but does not affect membrane potential or input resistance of hippocampal CA1 pyramidal cells. Kynurenic acid also antagonizes responses induced in the dentate gyrus by excitatory amino acids, particularly N-methyl-DL-aspartate and the endogenous excitant quinolinic acid. These results indicate that kynurenic acid antagonizes synaptic transmission probably by blocking postsynaptic transmitter receptors at putative amino acid mediated synapses.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acids / antagonists & inhibitors
  • Animals
  • Aspartic Acid / analogs & derivatives
  • Aspartic Acid / antagonists & inhibitors
  • Depression, Chemical
  • Hippocampus / drug effects*
  • Kynurenic Acid / pharmacology*
  • Male
  • N-Methylaspartate
  • Organ Specificity
  • Rats
  • Rats, Inbred Strains
  • Spinal Cord / drug effects*
  • Synapses / drug effects
  • Synaptic Transmission / drug effects*


  • Amino Acids
  • Aspartic Acid
  • N-Methylaspartate
  • Kynurenic Acid