Table 1.

mGluRs groups, common agonists and antagonists and effects

Receptor	Localization	Common agonist	Common antagonist	Convulsive seizures	Neurotransmitter release	Reference
mGlu1, mGlu5	Postsynaptic neurons, presynaptic terminals, glial cells	Nonselective (1S, 3R)-ACPD, (R,S)-CHPG, (S)-3,5-dihydrox-yphenylglycine, L-quisqualic acid	(S)–MCPG, (T) AIDA, (U) (S)-4CPG	Proconvulsive	Enhancement	Thomsen and Dalby, 1998; Tang et al., 2009; Gregory and Goudet, 2021
mGlu2, mGlu3	Presynaptic membranes, postsynaptic membranes, glial cells	Nonselective (1S, 3R)-ACPD, DCG-IV, pomaglumetad (S)-4-carboxy-3-hydroxyphenylglycine	CPPG, (S)–MCPG, (T) L-serine-O-phosphate	Anticonvulsant	Reduction	Folbergrova et al., 2001; Alexander and Godwin, 2006; Gregory and Goudet, 2021
mGlu4, mGlu6, mGlu7, mGlu8	Presynaptic membranes, presynaptic membranes, glutamatergic and GABAergic neurons, glial cells	ACPT-1, cinnabarinic acid, L-serine-O-phosphate’ (RS)-PPG, cyclobutylene AP5	CPPG, (S)–MCPG, (T) MSOP	Mixed responses	Reduction	Thomsen and Dalby, 1998; Folbergrova et al., 2001; Gregory and Goudet, 2021

(R, S)-PPG: (R,S)-4-phosphonophenylglycine; 1S,3R-ACPD: 1S,3R-1-aminocyclopentane-1,3-dicarboxylic acid; ACPT-1: (1S,3R,4S)-1-aminocyclopentane-1,2,4-tricarboxylic acid; AIDA: 1-aminoindan-1,5-dicarboxylic acid; CHPG: (R,S)-2-chloro-5-hydroxyphenylglycine; CPPG: α-cyclopropyl-4-phosphonophenylglycine; Cyclobutylene AP5: (RS)-1-amino-3-(phosphonomethylene) cyclobutene-carboxylic acid; DCG IV: (2S,2’R,3’R)-2-(2’,3’-dicarboxycyclopropyl)glycine; MCPG: α-methyl-4-carboxyphenylglycine; mGluR: metabotropic glutamate receptor; M-SOP: α-methylserine-O-phosphate; S-3,4-DCPG: (S)-3,4-dicarboxyphenylglycine. (S), (U), (T) represent the different relative configurations of the chiral centres.