A group II mGluR inhibitor (EC50s = 2.69 and 4.48 nM, respectively for mGluR2 and mGluR3); over 80-fold selectivity over group I and III mGluRs; no agonist or antagonist activity against NMDA, AMPA, or kainate receptors up to a concentration of 100 μM; raises extracellular dopamine level in the prefrontal cortex to 168% basal level in treated rats (3 mg/kg)