Metabolic imaging of human cognition: an fMRI/1H-MRS study of brain lactate response to silent word generation.
Proton magnetic resonance spectroscopy (1H-MRS) allows in vivo assessment of the metabolism related to human brain functions. Visual, auditory, tactile, and motor stimuli induce a temporary increase in the brain lactate level, which may act as a rapid source of energy for the activated neurons. The authors studied the metabolism of the frontal lobes during cognitive stimulation and measured local lactate levels with standard 1H-MRS, after localizing the activated area by functional MRI. Lactate levels were monitored while the subjects either silently listed numbers (baseline) or performed a silent word-generation task (stimulus-activation). The cognitive stimulus-activation produced a 50% increase in the brain lactate level in the left inferior frontal gyrus. The results show that metabolic imaging of neuronal activity related to cognition is possible using 1H-MRS.
Urrila
Anna S
AS
Institute of Biomedicine, University of Helsinki, Finland.
Hakkarainen
Antti
A
Heikkinen
Sami
S
Vuori
Kim
K
Stenberg
Dag
D
Häkkinen
Anna-Maija
AM
Lundbom
Nina
N
Porkka-Heiskanen
Tarja
T
D000328:Adult; D001921:Brain / Q000378:metabolism / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D005260:Female; D006801:Humans; D019344:Lactic Acid / Q000378:metabolism*; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D013060:Speech / Q000502:physiology
D019344:Lactic Acid