The role of group II metabotropic glutamate receptors in hippocampal CA1 long-term potentiation in vitro.
The role of group II metabotropic glutamate receptors (mGlu receptors) in mechanisms of long-term potentiation was investigated by analysis of excitatory postsynaptic field potentials of the CA1 region in rat hippocampal slices. The application of the group II agonists (2S,1'S,2'S)-2-(carboxycyclopropyl) glycine (L-CCG-I) and (2S,1'R,2'R,3'R)-2-(2',3'-dicarboxycyclopropyl) glycine (DCG IV) resulted in a dose-dependent reduction of long term potentiation in the concentration range 3-50 microM. In contrast to the effects of group II agonists on long-term potentiation, the group II antagonists (RS)-alpha-methyl-3-carboxy-4-hydroxy-phenylglycine (M3C4HPG) and (RS)-alpha-methylserine-O-phosphate monophenyl ester (MSOPPE) elicited a dose-dependent enhancement of long-term potentiation (50-100 microM or 20-50 microM, respectively). We conclude that group II mGlu receptors are not essential for the induction of long-term potentiation; however, they may be involved in feedback mechanisms in long-term potentiation.
Federal Institute for Neurobiology, Laboratory of Neuropharmacology, Magdeburg, Germany. behnisch@ifn-magdeburg.de
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D000600:Amino Acids, Dicarboxylic / Q000494:pharmacology*; D000818:Animals; D003521:Cyclopropanes / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology*; D005998:Glycine / Q000031:analogs & derivatives / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects* / Q000502:physiology; D017774:Long-Term Potentiation / Q000187:drug effects*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D018094:Receptors, Metabotropic Glutamate / Q000819:agonists* / Q000037:antagonists & inhibitors* / Q000502:physiology
D000600:Amino Acids, Dicarboxylic; D003521:Cyclopropanes; D018690:Excitatory Amino Acid Agonists; D018094:Receptors, Metabotropic Glutamate; C082313:2-(2,3-dicarboxycyclopropyl)glycine; C035261:(alpha-carboxycyclopropyl)glycine; D005998:Glycine