Cross-sectional Study of Glutamate in the Anterior Cingulate and Hippocampus in Schizophrenia.
BACKGROUND
There has been growing support for dysfunctions of the excitatory glutamatergic system and its implications for the psychophysiology of schizophrenia. However, previous studies reported mixed results regarding glutamate concentrations in schizophrenia with varying deviations across brain regions.


METHODS
We used an optimized proton magnetic resonance spectroscopy procedure to measure absolute glutamate concentrations in the left hippocampal region and the anterior cingulate cortex (ACC) in 29 medicated patients with schizophrenia and in 29 control participants without mental disorder.


RESULTS
The glutamate concentrations were significantly lower in the ACC but higher in the hippocampus of patients compared to controls. ACC and hippocampal glutamate concentrations correlated positively in patients but not in controls. ACC glutamate was weakly associated with Clinical Global Impression score and duration of illness in patients.


CONCLUSIONS
Glutamate concentrations in schizophrenia deviate from controls and show associations with disease severity. A higher concentration of hippocampal glutamate in schizophrenia compared to controls is shown. The association between ACC and hippocampus glutamate concentrations in patients with schizophrenia suggests an abnormal coupling of excitatory systems compared to controls as predicted by previous glutamate models of schizophrenia.
Clinic for Psychiatry and Psychotherapy, Charité University Medicine, St. Hedwig-Krankenhaus, Berlin, Germany; j.gallinat@uke.de.
Jürgen
J
Gallinat
Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin, Germany; Department of Psychology and Neuroscience, Duke University, Durham, NC;
Kibby
K
McMahon
Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin, Germany;
Simone
S
Kühn
Physikalisch-Technische Bundesanstalt (PTB), Berlin, Germany;
Florian
F
Schubert
Department of Psychiatry and Psychotherapy, University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany; Department of Psychiatry, Psychotherapy, Psychosomatics and Addiction Medicine, Essen, Germany.
Martin
M
Schaefer
D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism*; D006179:Gyrus Cinguli / Q000378:metabolism*; D006624:Hippocampus / Q000378:metabolism*; D006801:Humans; D008297:Male; D066244:Proton Magnetic Resonance Spectroscopy; D012559:Schizophrenia / Q000378:metabolism*; D012720:Severity of Illness Index
D018698:Glutamic Acid
MR spectroscopy; anterior cingulated; glutamate; glutamatergic hypothesis of schizophrenia; hippocampus; schizophrenia