Metabotropic glutamate receptor-induced homosynaptic long-term depression and depotentiation in the dentate gyrus of the rat hippocampus in vitro.
We have investigated the role of metabotropic glutamate receptors (mGluR) in the induction of homosynaptic long-term depression (LTD) and depotentiation (DP) in the dentate gyrus of the adult rat. Perfusion of the mGluR agonist (1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid (1S,3R-ACPD) for a prolonged period (20 min) induced long-term depression (LTD) of field excitatory postsynaptic field potentials (epsps) from the baseline level and also depotentiation (DP) from the long-term potentiated level. Both the ACPD-and the low frequency stimulation (LFS)-induced LTD and DP were inhibited in the presence of the mGluR antagonist (+)-alpha-methyl-4-carboxyphenylglycine (MCPG), demonstrating the necessity for the activation of metabotropic glutamate receptors in the induction of LTD/DP. The LFS and ACPD-induced LTD were independent of the activation of N-methyl-D-aspartate (NMDA) receptors, as they were not blocked by the NMDA receptor antagonist D-2-amino-5-phophonopentanoate (AP5).
Department of Physiology, Trinity College, Dublin, Ireland.
S M
SM
O'Mara
M J
MJ
Rowan
R
R
Anwyl
D000818:Animals; D003515:Cycloleucine / Q000031:analogs & derivatives / Q000494:pharmacology; D018891:Dentate Gyrus / Q000187:drug effects*; D003864:Depression, Chemical; D004558:Electric Stimulation; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D066298:In Vitro Techniques; D009473:Neuronal Plasticity / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D018094:Receptors, Metabotropic Glutamate / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000502:physiology*; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors; D017661:Receptors, Presynaptic / Q000187:drug effects
D018691:Excitatory Amino Acid Antagonists; D018094:Receptors, Metabotropic Glutamate; D016194:Receptors, N-Methyl-D-Aspartate; D017661:Receptors, Presynaptic; D003515:Cycloleucine; C036361:1-amino-1,3-dicarboxycyclopentane