title: Dynamic uncoupling and recoupling of perfusion and oxidative metabolism during focal brain activation in man.
abstract: Changes in glucose consumption, lactate production, and blood oxygenation were measured during prolonged neuronal activation (4-6 min) in human primary visual cortex using dynamic magnetic resonance spectroscopy and imaging. A decrease of steady-state glucose by 40% because of enhanced use by 21% was accompanied by a transient accumulation of lactate with a peak value of 170% 2.5 min after stimulation onset. Rapid blood hyperoxygenation indicating "uncoupling" of blood flow and oxidative metabolism was followed by a return to basal levels over 3 min. Thus, initial nonoxidative glucose consumption during functional activation is gradually complemented by a slower adjustment of oxidative phosphorylation that "recouples" perfusion and oxygen consumption at a new equilibrium.
authors.affiliation: Biomedizinische NMR Forschungs GmbH am Max-Planck-Institut für biophysikalische Chemie Am Fassberg 11, Göttingen, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Frahm
authors.forename: G
authors.initials: G
authors.lastname: Krüger
authors.forename: K D
authors.initials: KD
authors.lastname: Merboldt
authors.forename: A
authors.initials: A
authors.lastname: Kleinschmidt
mesh_terms: D000328:Adult; D002560:Cerebrovascular Circulation; D005947:Glucose / Q000378:metabolism; D006801:Humans; D007773:Lactates / Q000378:metabolism; D019344:Lactic Acid; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation; D014793:Visual Cortex / Q000378:metabolism* / Q000502:physiology
chemical_list: D007773:Lactates; D019344:Lactic Acid; D005947:Glucose; D010100:Oxygen