GRM2 and schizophrenia: As to this aspect, it could be of interest to evaluate whether the 5-HT2A-mGlu2/3 receptors crosstalk also occurs presynaptically in the hippocampus, a region which receives a diffuse serotonergic innervation from the raphe and where overt glutamatergicity is a common sign of most of the neurological disorders, including epilepsy and schizophrenia.