Table 4.

Group III mGlu receptor ligand and their impact on transmitter exocytosis.

Ligands	Pharmacological Profile	Impact on Glutamate Release	Impact on GABA Release	Refs.
l-AP4	Broad spectrum agonist of group III mGlu	⇓ 1 mM 4-AP-induced exocytosis	⇓ 12 mM KCl-evoked exocytosis	[134-137, 141]
AMN082	mGlu7 positive allosteric modulator	⇓, 1 mM 4-AP-induced exocytosis	⇓ 12 mM KCl-evoked exocytosis	[138, 141]
MPPIP	mGlu7 negative allosteric modulator	⇑ AMN082-mediated inhibition of 1 mM 4-AP-induced exocytosis	⇑ AMN082-mediated inhibition of 1 mM 4-AP-induced exocytosis	[138, 141]

⇓ = inhibition of transmitter release; ⇑ = reversal of the inhibition of transmitter release.