Investigating the metabolic changes due to visual stimulation using functional proton magnetic resonance spectroscopy at 7 T

J Cereb Blood Flow Metab. 2012 Aug;32(8):1484-95. doi: 10.1038/jcbfm.2012.33. Epub 2012 Mar 21.


Proton magnetic resonance spectroscopy ((1)H-MRS) has been used to demonstrate metabolic changes in the visual cortex on visual stimulation. Small (2% to 11%) but significant stimulation induced increases in lactate, glutamate, and glutathione were observed along with decreases in aspartate, glutamine, and glycine, using (1)H-MRS at 7 T during single and repeated visual stimulation. In addition, decreases in glucose and increases in γ-aminobutyric acid (GABA) were seen but did not reach significance. Changes in glutamate and aspartate are indicative of increased activity of the malate-aspartate shuttle, which taken together with the opposite changes in glucose and lactate, reflect the expected increase in brain energy metabolism. These results are in agreement with those of Mangia et al. In addition, increases in glutamate and GABA coupled with the decrease in glutamine can be interpreted in terms of increased activity of the neurotransmitter cycles. An entirely new observation is the increase of glutathione during prolonged visual stimuli. The similarity of its time course to that of glutamate suggests that it may be a response to the increased release of glutamate or to the increased production of reactive oxygen species. Together, these observations constitute the most detailed analysis to date of functional changes in human brain metabolites.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Energy Metabolism*
  • Female
  • Humans
  • Magnetic Resonance Spectroscopy*
  • Male
  • Neurotransmitter Agents / metabolism*
  • Photic Stimulation* / methods
  • Protons
  • Time Factors
  • Visual Cortex / metabolism*


  • Neurotransmitter Agents
  • Protons