Drugs that produce pathologically elevated release of glutamate and asynchronous PFC neural activity, including ketamine, PCP, and MK-801, are used widely to experimentally induce schizophrenia-like impairments in animal models, which are normalized by mGluR2/3 agonists (Moghaddam et al., 1997; Moghaddam and Adams, 1998; Lorrain et al., 2003; Jackson et al., 2004; Homayoun et al., 2005; Benneyworth et al., 2007; for review, see Maksymetz et al., 2017). Here, GRM2 is linked to schizophrenia.