Internalization of ionotropic glutamate receptors in response to mGluR activation

Activation of group 1 metabotropic glutamate receptors (mGIuRs) stimulates dendritic protein synthesis and long-term synaptic depression (LTD), but it remains unclear how these effects are related. Here we provide evidence th at a consequence of mGluR activation in the hippocampus is the rapid loss o f both AMPA and NMDA receptors from synapses. Like mGluR-LTD, the stable ex pression of this change requires protein synthesis. These data suggest that expression of mGluR-LTD is at least partly postsynaptic, and that a functi onal consequence of dendritic protein synthesis is the regulation of glutam ate receptor trafficking.