High-resolution mapping of iso-orientation columns by fMRI.
Blood-oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) is an important tool for localizing brain functions in vivo. However, the ability of BOLD fMRI to map cortical columnar structures is highly controversial, as the ultimate functional specificity of BOLD remains unknown. Here we report a biphasic BOLD response to visual stimulation in the primary visual cortex of cats. In functional imaging, the initial BOLD signal decrease accurately labeled individual iso-orientation columns. In contrast, the delayed positive BOLD changes indicated the pattern of overall activation in the visual cortex, but were less suited to discriminate active from inactive columns.
Kim
D S
DS
Center for Magnetic Resonance Research, University of Minnesota Medical School, 2021 6th Street S.E., Minneapolis, Minnesota 55455, USA.
Duong
T Q
TQ
Kim
S G
SG
D000818:Animals; D001931:Brain Mapping / Q000379:methods*; D002415:Cats; D008279:Magnetic Resonance Imaging / Q000379:methods; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted; D014793:Visual Cortex / Q000098:blood supply / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology; D014796:Visual Perception / Q000502:physiology
D010100:Oxygen