In the present study, we aimed at determining the metabolic responses of the human visual cortex during the presentation of chromatic and achromatic stimuli, known to preferentially activate two separate clusters of neuronal populations (called "blobs" and "interblobs") with distinct sensitivity to color or luminance features. Since blobs and interblobs have different cytochrome-oxidase (COX) content and micro-vascularization level (i.e., different capacities for glucose oxidation), different functional metabolic responses during chromatic vs. achromatic stimuli may be expected. The stimuli were optimized to evoke a similar load of neuronal activation as measured by the bold oxygenation level dependent (BOLD) contrast. Metabolic responses were assessed using functional 1H MRS at 7 T in 12 subjects. During both chromatic and achromatic stimuli, we observed the typical increases in glutamate and lactate concentration, and decreases in aspartate and glucose concentration, that are indicative of increased glucose oxidation. However, within the detection sensitivity limits, we did not observe any difference between metabolic responses elicited by chromatic and achromatic stimuli. We conclude that the higher energy demands of activated blobs and interblobs are supported by similar increases in oxidative metabolism despite the different capacities of these neuronal populations.

• Klíčová slova
• MR spectroscopy, energy metabolism, functional MRI, glutamate, lactate,
• MeSH
• barva * MeSH
• energetický metabolismus MeSH
• glukosa metabolismus   MeSH
• kyselina asparagová metabolismus   MeSH
• kyselina glutamová metabolismus   MeSH
• kyselina mléčná metabolismus   MeSH
• lidé MeSH
• magnetická rezonanční spektroskopie MeSH
• magnetická rezonanční tomografie MeSH
• mozek - chemie fyziologie   MeSH
• neurony fyziologie   MeSH
• oxidace-redukce MeSH
• respirační komplex IV metabolismus   MeSH
• světelná stimulace * MeSH
• zdraví dobrovolníci pro lékařské studie MeSH
• zrakové evokované potenciály MeSH
• zrakové korové centrum metabolismus   fyziologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• glukosa MeSH
• kyselina asparagová MeSH
• kyselina glutamová MeSH
• kyselina mléčná MeSH
• respirační komplex IV MeSH