title: Contributions of quisqualate and NMDA receptors to the induction and expression of LTP.
abstract: The contributions of two subclasses of excitatory amino acid transmitter receptors to the induction and expression of long-term potentiation (LTP) were analyzed in hippocampal slices. The quisqualate/kainate receptor antagonist DNQX (6,7-dinitro-quinoxaline-2,3-dione) blocked 85% of the evoked field potential, leaving a small response that was sensitive to D-AP5 (D-2-amino-5-phosphonopentanoate), an N-methyl-D-aspartate (NMDA) receptor blocker. This residual D-AP5-sensitive response was of comparable size in control and previously potentiated inputs. High-frequency stimulation in the presence of DNQX did not result in the development of robust LTP. Washout of the drug, however, revealed the potentiation effect. Thus NMDA-mediated responses can induce, but are not greatly affected by, LTP; non-NMDA receptors, conversely, mediate responses that are not needed to elicit LTP but that are required for its expression.
authors.affiliation: Center for the Neurobiology of Learning and Memory, University of California, Irvine 92717.
authors.forename: D
authors.initials: D
authors.lastname: Muller
authors.forename: M
authors.initials: M
authors.lastname: Joly
authors.forename: G
authors.initials: G
authors.lastname: Lynch
mesh_terms: D015763:2-Amino-5-phosphonovalerate; D000818:Animals; D004553:Electric Conductivity; D004558:Electric Stimulation; D005071:Evoked Potentials / Q000187:drug effects; D006624:Hippocampus / Q000502:physiology*; D008274:Magnesium / Q000494:pharmacology; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate; D017981:Receptors, Neurotransmitter / Q000187:drug effects / Q000502:physiology*; D013569:Synapses / Q000502:physiology*; D014633:Valine / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D011810:Quinoxalines; D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate; D017981:Receptors, Neurotransmitter; C056723:FG 9041; D015763:2-Amino-5-phosphonovalerate; D014633:Valine; D008274:Magnesium