title: Preliminary findings of proton magnetic resonance spectroscopy in occipital cortex during sleep deprivation.
abstract: Proton magnetic resonance spectroscopy ((1)H MRS) has revealed biochemical alterations in various psychiatric disorders. Changes in brain metabolites may be caused not only by the disease's progression or response to treatment, but also by physiological variability. The aim of this study was to use (1)H MRS to assess the effects of specific short-term physiological states on major metabolites. Eight healthy women underwent (1)H MRS at the beginning and end of a 40-h period of sleep deprivation. The ratios of N-acetyl-aspartate (NAA), total creatine (tCr), and choline-containing compounds (Cho) to water (H(2)O) were determined from the occipital cortex during both baseline and photic stimulation conditions. During sleep deprivation, NAA/H(2)O decreased by 7% and Cho/H(2)O by 12%. Photic stimulation had no effect on the measured metabolites in the alert state, but in the sleep-deprived state the level of Cho/H(2)O increased during neuronal activation. The results suggest that NAA/H(2)O and Cho/H(2)O may depend on the state of alertness.
authors.affiliation: Institute of Biomedicine, University of Helsinki, Finland. anna.urrila@helsinki.fi
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: Outi
authors.initials: O
authors.lastname: Huhdankoski
authors.forename: Tuomo
authors.initials: T
authors.lastname: Kuusi
authors.forename: Dag
authors.initials: D
authors.lastname: Stenberg
authors.forename: Anna-Maija
authors.initials: AM
authors.lastname: Häkkinen
authors.forename: Tarja
authors.initials: T
authors.lastname: Porkka-Heiskanen
authors.forename: Nina
authors.initials: N
authors.lastname: Lundbom
mesh_terms: D000328:Adult; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D002794:Choline / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D004569:Electroencephalography; D004734:Energy Metabolism / Q000502:physiology; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D009778:Occipital Lobe / Q000378:metabolism* / Q000503:physiopathology*; D010775:Photic Stimulation / Q000379:methods; D011522:Protons; D012892:Sleep Deprivation / Q000503:physiopathology*; D013997:Time Factors; D014851:Wakefulness / Q000502:physiology
chemical_list: D011522:Protons; D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline