The combined mGlu2 PAM/5HT2A antagonistic activity of JNJ-40411813 is of particular interest since both serotonin 5HT2A and mGlu2 receptors have been implicated in the pathophysiology of schizophrenia, as well as in the mechanism of action of hallucinogenics (Aghajanian 2009; Gonzalez-Maeso and Sealfon 2009). Here, GRM2 is linked to schizophrenia.