Translational and developmental perspective on N-methyl-D-aspartate synaptic deficits in schizophrenia

Schizophrenia has long been approached from a translational perspective; however, new findings from the past decade have radically affected the dominant accounts of this illness. It is now possible to derive a consistent account of one contributing cause of schizophrenia across multiple levels of analysis, from genes to receptors, functional neuroanatomy, cognition, and symptoms. To this end, we summarize the data attributing the disorganization symptoms of schizophrenia to a failure of executive, prefrontal cortical processes. We describe the hypothesis that this failure reflects an impairment in N-methyl-D-aspartate (NMDA) glutamatergic neurotransmission, that is likely to involve both the dysregulated function of NMDA synapses, as well as the physical loss of NMDA synapses, particularly in prefrontal cortex. Dysregulation in NMDA synaptic function can be in turn attributed to polymorphisms in a variety of genes (regulator of G-protein signaling 4, dystrobrevin binding protein I, neuregulin-1, D-amino acid oxidase activator, and others) that have been linked to schizophrenia and are likely to impact NMDA-mediated synaptic neuroplasticity. Although the science of schizophrenia is not yet at a point where any domain or set of findings provides strong constraints across other levels of analysis, the further development of evidence for this chain of causation can provide increasingly strong tests of the NMDA synapse deficit theory.