Cellular/molecular coincident activation of metabotropic glutamate receptors and NMDA receptors (NMDARs) downregulates perisynaptic/extrasynaptic NMDARs and enhances high-fidelity neurotransmission at the developing calyx of the held synapse - Joshi, I; Yang, Y-M; Wang, L-Y (J Neurosci, 2007)