Related Experiment Video
Updated: Jan 29, 2026

Cardiac Magnetic Resonance Imaging at 7 Tesla
Published on: January 6, 2019
Metabolite concentration changes associated with positive and negative BOLD responses in the human visual cortex: A
Yohan Boillat1, Lijing Xin2, Wietske van der Zwaag2,3
1Laboratory for Functional and Metabolic Imaging, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
Abstract:
Negative blood oxygenation-level dependent (BOLD) signal observed during task execution in functional magnetic resonance imaging (fMRI) can be caused by different mechanisms, such as a blood-stealing effect or neuronal deactivation. Electrophysiological recordings showed that neuronal deactivation underlies the negative BOLD observed in the occipital lobe during visual stimulation. In this study, the metabolic demand of such a response was studied by measuring local metabolite concentration changes during a visual checkerboard stimulation using functional magnetic resonance spectroscopy (fMRS) at 7 Tesla. The results showed increases of glutamate and lactate concentrations during the positive BOLD response, consistent with previous fMRS studies. In contrast, during the negative BOLD response, decreasing concentrations of glutamate, lactate and gamma-aminobutyric acid (GABA) were found, suggesting a reduction of glycolytic and oxidative metabolic demand below the baseline. Additionally, the respective changes of the BOLD signal, glutamate and lactate concentrations of both groups suggest that a local increase of inhibitory activity might occur during the negative BOLD response.
Related Concept Videos
Positive, Negative, and Zero Work
Positive and Negative Feedback Loops
Position-effect Variegation
The Integrated Rate Law: The Dependence of Concentration on Time
Concentration Cells
Consider the following voltaic cell:
Chromatin Position Affects Gene Expression
Topologically Associated Domains (TADs)
The 3-dimensional positioning of chromatin in the nucleus influences the...

