GRM3 and schizophrenia: Specifically, the Group II mGlu receptors (mGlu2 and mGlu3) have been identified as novel targets in the treatment of schizophrenia upon the inaugural discovery that administration of the Group II selective orthosteric agonist LY354740 ameliorates psychotic behaviours (Moghaddam and Adams, 1998; Aghajanian and Marek, 1999).