Group II Metabotropic Glutamate Receptors

Group II Metabotropic Glutamate Receptors

Metabotropic glutamate receptors are classified as “family 3’’ G-protein coupled receptors (GPCRs). Group II metabotropic receptors (that include mGluR2 and mGluR3 receptors) are ne-gatively coupled to adenylate cyclase, and the mGluR2 receptor subclass is found both pre- and extrasynaptically. Several lines of evidence indicate that glutamate activates these mGluR2 receptors, resulting in a rapid inhibition of glutamate release, creating a negative feedback loop (Schoepp, 2001; Scanzfani et al., 1997). Since activation of Group II metabotropic recep-tors appears to require an elevated glutamate concentration, an agonist at these receptors would effectively dampen glutama-tergic transmission (including activation of NMDA receptors) without remarkably affecting synaptic glutamate under resting conditions.

Based on these data and reports that telencephalic glutamate concentrations are rapidly elevated during stress