Relationship of energy metabolism detected by 31P-MRS in the human brain with mental fatigue.
To search for a possible relationship between brain energy metabolism and mental fatiguability, 10 normal volunteers were examined by 31P-MRS (phosphorus-31 magnetic resonance spectroscopy) in the occipital cortex during photic stimulation (PS), and Uchida-Kraepelin test (UKT), a standardized serial calculation task, was used for measurement of intraindividual characteristics of mental fatigue in these subjects. More decrease of phosphocreatine measured by 31P-MRS during the PS was significantly associated with more effects of rest assessed by UKT (r = -0.86, p <0.005). More decrease in pH after PS was associated with steeper decline of performance (r = 0.78, p <0.01). These findings suggest that characteristics of brain energy metabolism in an individual may relate to intrinsic patterns of mental fatigability.
Kato
T
T
Department of Neuropsychiatry, Faculty of Medicine, University of Tokyo, Japan. tadafumi-tky@umin.ac.jp
Murashita
J
J
Shioiri
T
T
Inubushi
T
T
Kato
N
N
D000328:Adult; D001923:Brain Chemistry / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D005222:Mental Fatigue / Q000378:metabolism*; D009778:Occipital Lobe / Q000378:metabolism; D010725:Phosphocreatine / Q000378:metabolism; D010759:Phosphorus Isotopes; D010775:Photic Stimulation; D011597:Psychomotor Performance
D010759:Phosphorus Isotopes; D010725:Phosphocreatine