This document summarizes several studies that used proton magnetic resonance spectroscopy to measure glutamate and glutamine levels in the prefrontal cortex of individuals with schizophrenia compared to healthy controls. Across three studies with a total of 47 schizophrenia patients and 49 healthy controls, individuals with schizophrenia consistently showed elevated levels of glutamine or a combined measure of glutamate and glutamine in the medial prefrontal cortex compared to controls. A separate study also found elevated levels of these neurotransmitters in the dorsolateral prefrontal cortex of schizophrenia patients.

1. Glutamate-Glutamine in Schizophrenia measured with
Proton Magnetic Resonance Spectroscopy
Lawrence S. Kegeles
Psychiatry and Radiology,
Columbia University
NY State Psychiatric Institute

2. Prefrontal cortex glutamine (Gln) or Glu-Gln (Glx) in
Schizophrenia - Proton (1H) MRS studies
N Outcome
STUDY Med Status MPFC
pt / hc measure
Bartha et al., Archives 1997 10 / 10 naïve Gln
Théberge et al., AJP 2002 21 / 21 naïve Gln
Théberge et al., Br J Psychiatry 2007 13 / 16 naïve Gln
9 naïve, 7
Kegeles et al., Archives 2012 16 / 22 Glx
unmedicated

3. MRS voxels
MPFC
DLPFC

4. Glx levels in schizophrenia
n = 22
n = 16
n = 16
MPFC DLPFC
DLPFC
(Kegeles et al., Arch Gen Psychiatry, 2012)

5. Glx levels in healthy humans (n = 12) -
response to ketamine infusion
MPFC