Abstract #0790

Correlation Between MEG Gamma Phase Locking and 1H-MRS Determined Temporal Lobe GABA in Subjects with Schizophrenia and Normal Controls

Mark S. Brown¹, Peter Teale², Dan Collins², Bryce Pasko², Debra Singel³, Don C. Rojas², Martin Reite²

¹Radiology, University of Colorado Denver, Aurora, CO, United States; ²Psychiatry, University of Colorado Denver, Aurora, CO, United States; ³Brain Imaging Center, University of Colorado Denver, Aurora, CO, United States

Magnetoencephalography (MEG) recordings of neural oscillations of the gamma band (~40 Hz) phase locking factor (PLF) yield a number that measures how well the response coincides with the stimulus in time. Schizophrenic subjects show impaired tracking ability compared to controls. We have measured the GABA levels in the temporal lobe (auditory cortex) of schizophrenics using J-edited 1H MRS and correlated them with the PLF. Schizophrenics show a negative correlation with PLF compared to the positive correlation exhibited by controls. The results suggest that the impairment is not due to lower levels of GABA, but rather impaired utilization by the schizophrenics.