title: High-Resolution Mapping of Myeloarchitecture In Vivo: Localization of Auditory Areas in the Human Brain.
abstract: The precise delineation of auditory areas in vivo remains problematic. Histological analysis of postmortem tissue indicates that the relation of areal borders to macroanatomical landmarks is variable across subjects. Furthermore, functional parcellation schemes based on measures of, for example, frequency preference (tonotopy) remain controversial. Here, we propose a 7 Tesla magnetic resonance imaging method that enables the anatomical delineation of auditory cortical areas in vivo and in individual brains, through the high-resolution visualization (0.6 × 0.6 × 0.6 mm(3)) of intracortical anatomical contrast related to myelin. The approach combines the acquisition and analysis of images with multiple MR contrasts (T1, T2*, and proton density). Compared with previous methods, the proposed solution is feasible at high fields and time efficient, which allows collecting myelin-related and functional images within the same measurement session. Our results show that a data-driven analysis of cortical depth-dependent profiles of anatomical contrast allows identifying a most densely myelinated cortical region on the medial Heschl's gyrus. Analyses of functional responses show that this region includes neuronal populations with typical primary functional properties (single tonotopic gradient and narrow frequency tuning), thus indicating that it may correspond to the human homolog of monkey A1.
authors.affiliation: Department of Cognitive Neurosciences, Faculty of Psychology and Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, 55455 Minneapolis, MN, USA.
authors.forename: Federico
authors.initials: F
authors.lastname: De Martino
authors.affiliation: Department of Cognitive Neurosciences, Faculty of Psychology and Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands.
authors.forename: Michelle
authors.initials: M
authors.lastname: Moerel
authors.affiliation: Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, 55455 Minneapolis, MN, USA Icahn School of Medicine Mount Sinai, 10029-6574 New York, NY, USA.
authors.forename: Junqian
authors.initials: J
authors.lastname: Xu
authors.affiliation: Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, 55455 Minneapolis, MN, USA.
authors.forename: Pierre-Francois
authors.initials: PF
authors.lastname: van de Moortele
authors.affiliation: Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, 55455 Minneapolis, MN, USA.
authors.forename: Kamil
authors.initials: K
authors.lastname: Ugurbil
authors.affiliation: Department of Cognitive Neurosciences, Faculty of Psychology and Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands.
authors.forename: Rainer
authors.initials: R
authors.lastname: Goebel
authors.affiliation: Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, 55455 Minneapolis, MN, USA.
authors.forename: Essa
authors.initials: E
authors.lastname: Yacoub
authors.affiliation: Department of Cognitive Neurosciences, Faculty of Psychology and Neuroscience, Maastricht University, 6229 ER Maastricht, The Netherlands.
authors.forename: Elia
authors.initials: E
authors.lastname: Formisano
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D001303:Auditory Cortex / Q000033:anatomy & histology* / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology*; D001931:Brain Mapping / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009186:Myelin Sheath / Q000502:physiology*; D012815:Signal Processing, Computer-Assisted
keywords: auditory cortex; cortical myelin-related contrast; high-field MRI; tonotopy