Biomedical Frontiers: Winter/Spring 1996, Vol.3, No.2
Schizophrenia: Searching for answers
Magnetic Resonance Spectroscopy

Dr. Lawrence Kegeles is using magnetic resonance spectroscopy (MRS) to determine the concentration of the neurotransmitter glutamate in the brains of people with schizophrenia vs. normal controls. The idea that glutamate levels are abnormal in schizophrenia has been suggested since the 1980s. Results have been inconclusive, possibly in part due to anatomic specificity of glutamate abnormalities. Now, however, the new MRS technology makes it possible to test this hypothesis in vivo in what has been termed a "non-invasive biopsy" of selected brain regions.

Unlike traditional magnetic resonance imaging, MRS suppresses the water signals from human tissues and looks at signals from protons in other molecules. As a result, MRS allows researchers to identify levels of neurochemicals that occur in high enough concentrations in the brain, such as glutamate ("GLX "on graph to indicate its signal is combined with glutamine and GABA), says Dr. Kegeles, a postdoctoral clinical fellow and assistant in clinical psychiatry at P&S and a research fellow at NYSPI. MRS is a fairly new use of MRI technology; so far only a few studies have taken advantage of it, says Dr. Kegeles, who recently started a two-year clinical trial to examine the relationship between glutamate and schizophrenia. Subjects in the second year of the project will be studied at the new high-field facility at the Hatch MRI Center at the Neurological Insitute, which will allow improved resolution of the glutamate signal from nearby spectral peaks and quantification of differences detected between patient and control groups.