title: Metabolic imaging of human cognition: an fMRI/1H-MRS study of brain lactate response to silent word generation.
abstract: 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.
authors.affiliation: Institute of Biomedicine, University of Helsinki, Finland.
authors.forename: Anna S
authors.initials: AS
authors.lastname: Urrila
authors.forename: Antti
authors.initials: A
authors.lastname: Hakkarainen
authors.forename: Sami
authors.initials: S
authors.lastname: Heikkinen
authors.forename: Kim
authors.initials: K
authors.lastname: Vuori
authors.forename: Dag
authors.initials: D
authors.lastname: Stenberg
authors.forename: Anna-Maija
authors.initials: AM
authors.lastname: Häkkinen
authors.forename: Nina
authors.initials: N
authors.lastname: Lundbom
authors.forename: Tarja
authors.initials: T
authors.lastname: Porkka-Heiskanen
mesh_terms: 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
chemical_list: D019344:Lactic Acid