TY - JOUR
T1 - Sustained neuronal activation raises oxidative metabolism to a new steady-state level
T2 - Evidence from 1H NMR spectroscopy in the human visual cortex
AU - Mangia, Silvia
AU - Tkáč, Ivan
AU - Gruetter, Rolf
AU - Van De Moortele, Pierre Francois
AU - Maraviglia, Bruno
AU - Uǧurbil, Kâmil
PY - 2007/5/16
Y1 - 2007/5/16
N2 - To date, functional 1H NMR spectroscopy has been utilized to report the time courses of few metabolites, primarily lactate. Benefiting from the sensitivity offered by ultra-high magnetic field (7 T), the concentrations of 17 metabolites were measured in the human visual cortex during two paradigms of visual stimulation lasting 5.3 and 10.6 mins. Significant concentration changes of approximately 0.2 μmol/g were observed for several metabolites: lactate increased by 23%±5% (P<0.0005), glutamate increased by 3%±1% (P<0.01), whereas aspartate decreased by 15%±6% (P<0.05). Glucose concentration also manifested a tendency to decrease during activation periods. The lactate concentration reached the new steady-state level within the first minute of activation and came back to baseline only after the stimulus ended. The changes of the concentration of metabolites implied a rise in oxidative metabolism to a new steady-state level during activation and indicated that amino-acid homeostasis is affected by physiological stimulation, likely because of an increased flux through the malate-aspartate shuttle.
AB - To date, functional 1H NMR spectroscopy has been utilized to report the time courses of few metabolites, primarily lactate. Benefiting from the sensitivity offered by ultra-high magnetic field (7 T), the concentrations of 17 metabolites were measured in the human visual cortex during two paradigms of visual stimulation lasting 5.3 and 10.6 mins. Significant concentration changes of approximately 0.2 μmol/g were observed for several metabolites: lactate increased by 23%±5% (P<0.0005), glutamate increased by 3%±1% (P<0.01), whereas aspartate decreased by 15%±6% (P<0.05). Glucose concentration also manifested a tendency to decrease during activation periods. The lactate concentration reached the new steady-state level within the first minute of activation and came back to baseline only after the stimulus ended. The changes of the concentration of metabolites implied a rise in oxidative metabolism to a new steady-state level during activation and indicated that amino-acid homeostasis is affected by physiological stimulation, likely because of an increased flux through the malate-aspartate shuttle.
KW - BOLD
KW - Brain activation
KW - Functional metabolism
KW - H NMR spectroscopy
KW - In vivo
KW - Lactate
KW - Malate-aspartate shuttle
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U2 - 10.1038/sj.jcbfm.9600401
DO - 10.1038/sj.jcbfm.9600401
M3 - Article
C2 - 17033694
AN - SCOPUS:34247471119
SN - 0271-678X
VL - 27
SP - 1055
EP - 1063
JO - Journal of Cerebral Blood Flow and Metabolism
JF - Journal of Cerebral Blood Flow and Metabolism
IS - 5
ER -