Article date: 1991/6/1
PubMed ID: 1680482
Journal name: Neuroreport (ISSN: 0959-4965)
We have investigated the roles of glutamate (Glu) receptors in the mechanism of long-term potentiation observed in rat hippocampal mossy fiber synapses (MF-LTP). The mossy fiber responses were almost completely suppressed by ionotropic Glu receptor (iGluR) antagonists both before and after the induction of LTP. However, tetanic stimulation produced robust LTP even when the synaptic transmission was blocked postsynaptically by iGluR antagonists. In contrast, when the transmission was blocked presynaptically by Ca(2+)-free media, tetanic stimulation produced no LTP. D,L-2-amino-3-phosphono-propionate(D,L-AP3), a metabotropic Glu receptor (mGluR) antagonist, inhibited the induction of MF-LTP. Perfusion with ibotenate, a mGluR agonist, induced long-lasting enhancement of the mossy fiber responses without tetanic stimulation, and this ibotenate-induced potentiation was antagonized by D,L-AP3.
Author List: Ito I, Sugiyama H
Publication Types: Journal Article
Substances mentioned in the article: Quinoxalines; Receptors, Glutamate; Receptors, Neurotransmitter; 2-amino-3-phosphonopropionic acid; Ibotenic Acid; 6-Cyano-7-nitroquinoxaline-2,3-dione; Alanine;
Mesh terms: 6-Cyano-7-nitroquinoxaline-2,3-dione; Alanine/analogs & derivatives; Animals; Evoked Potentials/physiology; Hippocampus/cytology; Ibotenic Acid/pharmacology; In Vitro Techniques; Male; Perfusion; Pyramidal Tracts/cytology; Quinoxalines/pharmacology; Rats; Rats, Inbred Strains; Receptors, Glutamate; Receptors, Neurotransmitter/physiology; Synapses/physiology; Synaptic Transmission/drug effects;