Neurotransmitter changes during interference task in anterior cingulate cortex: evidence from fMRI-guided functional...

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Neuroimaging

Background:

• Blood oxygenation level-dependent (BOLD) signals indirectly reflect neural activity.
• Neurotransmitter flux is hypothesized to underlie BOLD responses.
• Investigating direct links between neurotransmitters and BOLD signals in vivo is crucial.

Purpose of the Study:

• To measure metabolite/BOLD associations during a cognitive task using fMRI-guided functional magnetic resonance spectroscopy (MRS).
• To investigate the relationship between GABA and glutamate levels and BOLD signal changes in the anterior cingulate cortex (ACC).

Main Methods:

• Used fMRI-guided MRS at 3 Tesla to measure GABA and glutamate concentrations in the ACC.
• Employed the SPECIAL pulse sequence for metabolite quantification.
• Aligned MRS voxel placement with individual BOLD activity during a manual Stroop task.

Main Results:

• GABA and glutamate levels exhibited inverted U-shaped patterns across task phases (before, during, after).
• Glutamine increased linearly, while total creatine remained stable.
• Increased GABA during the Stroop task correlated with ACC BOLD signal changes.

Conclusions:

• An fMRI-guided MRS approach demonstrated an association between increased inhibitory neurotransmitter (GABA) and BOLD signal changes.
• This methodology may enable in vivo investigation of neurotransmitter-BOLD associations in brain function and dysfunction.