MGS-0039 is a group II metabotropic glutamate receptor (mgluR2/3) antagonist. Antidepressant-like action of group II mGlu receptor antagonists does not depend on serotonergic system activation. However, the AMPA receptor seems to play a key role in the antidepressant-like action of these compounds. Dopamine release in the NAc shell is regulated by mGlu 2/3 receptors.