Mary Charlotte Stephenson1, Matthew J.
Brookes1, Darren Price1, Antonio Napolitano2,
Susan T. Francis1, Peter G. Morris1
1School of Physics &
Astronomy, University of Nottingham, Nottingham, Nottinghamshire, United
Kingdom; 2Academic Radiology, University of Nottingham, United
Kingdom
The peak frequency of stimulus-induced visual γ-oscillations, measured using magnetoencephalograpy, has been shown to be predicted by the resting concentration of γ-amino butyric acid (GABA). However, cortical network models show that the oscillatory frequency depends on the balance between excitatory and inhibitory neurotransmitters. In this study we utilize the increased spectral resolution and signal available at 7T to quantify glutamate, glutamine and GABA. Our results indicate a stronger correlation between γ-frequency and glutamate/GABA than for GABA alone. The strongest correlation was found for glutamine/GABA where the glutamine concentration is thought to be closely related to the glutamate neurotransmitter pool size