An antagonist of glutamate metabotropic receptors, (RS)-alpha-methyl-4-carboxyphenylglycine, prevents the LTP-related increase in postsynaptic AMPA sensitivity in hippocampal slices.

(RS)-alpha-methyl-4-carboxyphenylglycine (MCPG), a compound which selectively antagonizes metabotropic glutamate receptors (mGlu-R), presents the LTP of field excitatory postsynaptic potentials (fEPSP) as well as the tetanus-induced increase in AMPA-evoked responses (fPRs) in the CA1 region of hippocampal slices. This effects of MCPG provide evidence for the involvement of mGlu-Rs in mechanisms underlying the postsynaptic maintenance of LTP, which appears to be mediated, at least partially, by an increase in sensitivity and/or number of postsynaptic AMPA receptors.