title: Towards a neurochemical profile of the amygdala using short-TE1H magnetic resonance spectroscopy at 3 T.
abstract: The amygdala plays a key role in emotional learning and in the processing of emotions. As disturbed amygdala function has been linked to several psychiatric conditions, a knowledge of its biochemistry, especially neurotransmitter levels, is highly desirable. The spin echo full intensity acquired localized (SPECIAL) sequence, together with a transmit/receive coil, was used to perform very short-TE magnetic resonance spectroscopy at 3 T to determine the neurochemical profile in a spectroscopic voxel containing the amygdala in 21 healthy adult subjects. For spectral analysis, advanced data processing was applied in combination with a macromolecule baseline measured in the anterior cingulate for spectral fitting. The concentrations of total N-acetylaspartate, total creatine, total choline, myo-inositol and, for the first time, glutamate were quantified with high reliability (uncertainties far below 10%). For these metabolites, the inter-individual variability, reflected by the relative standard deviations for the cohort studied, varied between 12% (glutamate) and 22% (myo-inositol). Glutamine and glutathione could also be determined, albeit with lower precision. Retest on four subjects showed good reproducibility. The devised method allows the determination of metabolite concentrations in the amygdala voxel, including glutamate, provides an estimation of glutamine and glutathione, and may help in the study of disturbed amygdala metabolism in pathologies such as anxiety disorder, autism and major depression.
authors.affiliation: Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Schubert
authors.affiliation: Max Planck Institute for Human Development, Center for Lifespan Psychology, Berlin, Germany.|Universitätsklinikum Hamburg-Eppendorf, Department of Psychiatry and Psychotherapy, Hamburg, Germany.
authors.forename: Simone
authors.initials: S
authors.lastname: Kühn
authors.affiliation: Universitätsklinikum Hamburg-Eppendorf, Department of Psychiatry and Psychotherapy, Hamburg, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Gallinat
authors.affiliation: Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, Germany.|Charité-Universitätsmedizin Berlin, Center for Stroke Research Berlin (CSB), Berlin, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Mekle
authors.affiliation: Physikalisch-Technische Bundesanstalt (PTB), Braunschweig and Berlin, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Ittermann
mesh_terms: D000328:Adult; D000465:Algorithms; D000679:Amygdala / Q000737:chemistry*; D001704:Biopolymers / Q000032:analysis*; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D057054:Molecular Imaging / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted
chemical_list: D001704:Biopolymers
keywords: amygdala; glutamate; glutamine; glutathione; magnetic resonance spectroscopy