Glutamatergic neurotransmission involves structural and clinical deficits of schizophrenia

Background: Phencyclidine and ketamine induce a syndrome closely resembling schizophrenia due to their blockade of N-methyl- -aspartate (NMDA) receptor. These findings suggested that some aspects of schizophrenia are associated with decreased NMDA–glutamatergic function. We hypothesized that structural and symptomatic deficits in schizophrenia are related to glutamatergic neurotransmission. Methods: We studied the relationships among cerebrospinal fluid (CSF) glutamatergic markers, clinical presentation of schizophrenia, and CT parameters of brain structure in drug-free schizophrenics. Results: We found no significant differences between patients with schizophrenia and controls in CSF glutamatergic markers. When patients with schizophrenia were considered as a group, significant negative correlations between glutamatergic markers and brain structural measures as well as clinical measures were observed. Cluster analysis reveals a group of lower indices of glutamatergic neurotransmission, and more prominent thought disorder as well as ventricular enlargement, and a group with increased glutamate level. Conclusions: The findings support the hypothesis that altered glutamatergic neurotransmission plays a role in the brain structure and the clinical symptoms of schizophrenia.