Developmental changes in the effects of metabotropic glutamate receptor antagonists on CA1 long-term potentiation in rat hippocampal slices.

The effects of 100 microM D,L-2-amino-3-phosphonopropionate (AP3), 100 microM D,L-2-amino-4-phosphonobutyric acid (AP4), and 500 microM (R,S)-alpha-methyl-4-carboxyphenylglycine (MCPG), inhibitors of phosphoinositide (PI) turnover mediated by metabotropic glutamate receptors (mGluRs), on the induction of long-term potentiation (LTP) were examined in the CA1 region of hippocampal slices prepared from 15, 30 and 60 day old rats. In 15 or 30 day old rats, AP3 and MCPG applied for 5 min immediately after tetanization inhibited LTP. AP4 was less effective. All inhibitors were ineffective against LTP in 60 day old rats. These data support the hypothesis that the role of metabotropic glutamate receptors in LTP induction is influenced by development.