Low concentrations of N-methyl-D-aspartate inhibit the induction of long-term potentiation in rat hippocampal slices

Neurosci Lett. 1992 Mar 30;137(2):245-8. doi: 10.1016/0304-3940(92)90414-3.


We have examined the effects of excitatory amino acids on tetanus-induced long-term potentiation (LTP) in the CA1 region of rat hippocampal slices. Agonists acting at N-methyl-D-aspartate (NMDA) receptors, including NMDA, aspartate and glutamate, completely block the development of LTP when administered for 5 min prior to tetanic stimulation. Additionally, and unlike the NMDA receptor antagonist 2-amino-5-phosphonovalerate (APV), NMDA blocks LTP when administered for 5 min immediately following the electrical tetanus. The effective concentrations of NMDA are subthreshold for depolarizing CA1 neurons. These results indicate that under certain conditions NMDA receptor activation prevents CA1 LTP.

Publication types

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

MeSH terms

  • 2-Amino-5-phosphonovalerate / pharmacology
  • Amino Acids / physiology
  • Animals
  • Electric Stimulation
  • Evoked Potentials / drug effects
  • Evoked Potentials / physiology
  • Hippocampus / drug effects
  • Hippocampus / physiology*
  • In Vitro Techniques
  • Male
  • N-Methylaspartate / pharmacology*
  • Rats
  • Synapses / drug effects
  • Synapses / physiology


  • Amino Acids
  • N-Methylaspartate
  • 2-Amino-5-phosphonovalerate