Table 2.

mGluRs in the control of synaptic plasticity

mGluR type	Role in synaptic plasticity	References
mGluR1	Modulates NMDAR-LTP; independent LTP induction; LTD induction; its deletion models report LTP deficits; its inhibition reduced microglial phagocytosis of glutamate synapses	[67, 77, 159]
mGluR5	Modulates NMDAR-LTP; independent LTP induction; LTD induction; its ablation in astrocytes impairs high-frequency glutamate uptake and also reduces CA1 LTP	[66, 71, 77]
mGluR2	Stimulates LTD at GABAergic synapses; suppresses synaptic transmission transiently at CA3 synapse of mossy fibers	[48, 194, 195]
mGluR3	Regulates both LTP and LTD based upon its synaptic location; Stimulates chemical LTD while suppressing LTP upon activation in vitro; LTP induction at electrical synapses (eLTP)	[48, 181, 196]
mGluR4	Inhibits LTP; contributes to synaptic transmission inhibition at piriform cortex synapse in L-AP4 challenged olfactory bulb	[90, 197]
mGluR7	Inhibits LTP; known to induce activity regulated plasticity and reported to induce LTD in interneurons of stratum radiatum	[90, 198]
mGluR8	Inhibits LTP; primarily regulates the synaptic transmission in forebrain; KO mice exhibit anxiety-like behavior	[64, 199]