GRM2 and schizophrenia: Among the newly identified mGlu2-interacting proteins, we focused on the RTK TrkB that displayed a robust and reproducible enrichment in the mGlu2 interactome, in view of (i) the decreased expression of TrkB and its natural ligand BDNF in patients with schizophrenia in comparison to general population (15), (ii) the association of BDNF Val66Met polymorphism that alters BDNF secretion and schizophrenia (38), and (iii) the ability of a specific TrkB agonist to reverse cognitive and synaptic plasticity deficits in a rat model of schizophrenia (39).