Recent studies aimed at identifying the mechanisms that regulate the signal
ing of metabotropic glutamate receptors (mGluRs) have revealed that both pr
otein kinase and protein phosphatase activity are important in directly mod
ulating mGluR function. The inter-relationship between phosphorylation and
dephosphorylation of mGluRs seems to be an important determinant in regulat
ing mGluR function and the subsequent neuromodulatory events elicited by ac
tivation of mGluRs.