High-resolution fMRI maps of cortical activation in nonhuman primates

Correlation with intrinsic signal optical images

Anna Roe, Li M. Chen

Research output: Contribution to journalArticle

Abstract

One of the most widely used functional brain mapping tools is blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI). This method has contributed to new understandings of the functional roles of different areas in the human brain. However, its ability to map cerebral cortex at high spatial (submillimeter) resolution is still unknown. Other methods such as single- and multiunit electrophysiology and intrinsic signal optical imaging have revealed submillimeter resolution of sensory topography and cortical columnar activations. However, they are limited either by spatial scale (electrophysiology characterizes only local groups of neurons) or by the inability to monitor deep structures in the brain (i.e., cortical regions buried in sulci or subcortical structures). A method that could monitor all regions of the brain at high spatial resolution would be ideal. This capacity would open the doors to investigating, for example, how networks of cerebral cortical columns relate to or produce behavior. In this article we demonstrate that, without benefit of contrast agents, at a magnetic field strength of 9.4 tesla, BOLD fMRI can reveal millimeter-sized topographic maps of digit representation in the somatosensory cortex of the anesthetized squirrel monkey. Furthermore, by mapping the "funneling illusion," it is possible to detect even submillimeter shifts in activation in the cortex. Our data suggest that at high magnetic field strength, the positive BOLD signal can be used to reveal high spatial resolution maps of brain activity, a finding that weakens previous notions about the ultimate spatial specificity of the positive BOLD signal.

Original languageEnglish (US)
Pages (from-to)116-123
Number of pages8
JournalILAR Journal
Volume53
Issue number1
StatePublished - 2012
Externally publishedYes

Fingerprint

magnetic resonance imaging
Primates
Brain
Blood
Chemical activation
Magnetic Resonance Imaging
Oxygen
Electrophysiology
brain
oxygen
Magnetic Fields
electrophysiology
blood
magnetic fields
Brain mapping
Magnetic fields
Brain Mapping
cortex
Saimiri
Aptitude

Keywords

  • Digits
  • fMRI
  • Optical imaging
  • Primate
  • So-matosensory cortex
  • Topography

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Animal Science and Zoology

Cite this

High-resolution fMRI maps of cortical activation in nonhuman primates : Correlation with intrinsic signal optical images. / Roe, Anna; Chen, Li M.

In: ILAR Journal, Vol. 53, No. 1, 2012, p. 116-123.

Research output: Contribution to journalArticle

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