A 1H-MR spectroscopy study of changes in glutamate and glutamine (Glx) concentrations in frontal spectra after administration of memantine

Research Area: Research Year: 2009
Type of Publication: Article Keywords: cognitive control, fMRI, glutamate and glutamine, 1H-MR spectroscopy, memantine
Authors: van Wageningen, Heidi; Jørgensen, H A; Specht, Karsten; Hugdahl, Kenneth
Glutamate is the major excitatory neurotransmitter in the brain and therefore important for cognitive functions. The aim of the study was to investigate if administration of the N-methyl-D-aspartate receptor antagonist memantine to healthy individuals would affect brain activation when performing an auditory attention task. The task was a variant of a dichotic listening task with different instructions that tap demands for attention and cognitive control. We asked the question if memantine administration would lead to reduction in glutamatergic neurotransmission in areas related to attention and cognitive control. Left and right frontal glutamate and glutamine (Glx) concentrations were measured, using 1H-MR spectroscopy. Twenty-five healthy adults were scanned twice in a counterbalanced design, either drug naive or after administration of memantine for 21 days. The results showed that memantine significantly reduced Glx concentrations, and this reduction was associated with a reduction in brain activation in prefrontal cortex, which could have implications for understanding the neuronal mechanisms underlying higher cognitive functions such as cognitive control.
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