Evidences on the key role of the metabotrobic glutamatergic receptors in the pathogenesis of schizophrenia: a "breakthrough" in pharmacological treatment

The metabotropic glutamate receptors (mGluRs) are expressed pre- and post synaptically throughout the nervous system where they serve as modulators of synaptic transmission and neuronal excitability. The glutamatergic system is involved in a wide range of physiological processes in the brain, and its dysfunction plays an important role in the etiology and pathophysiology of psychiatric disorders, including schizophrenia. This paper reviews the neurodevelopmental origin and genetic susceptibility of schizophrenia relevant to NMDA receptor neurotransmission, and discusses the relationship between NMDA hypofunction and different domains of symptom in schizophrenia as well as putative treatment modality for the disorder. mGlu receptors have been hypothesizes as attractive therapeutic targets for the development of novel interventions for psychiatric disorders. Group II of mGlu receptors are of particular interest because of their unique distribution and the regulatory roles they have in neurotransmission. The glutamate hypothesis of schizophrenia predicts that agents that restore the balance in glutamatergic neurotransmission will ameliorate the symptomatology associated with this illness. Development of potent, efficacious, systemically active drugs will help to address the antipsychotic potential of these novel therapeutics. This review will discuss recent progress in elucidating the pharmacology and function of group II receptors in the context of current hypotheses on the pathophysiology of schizophrenia and the need for new and better antipsychotics.