Neuroscience 2000 Abstract
| Presentation Number: | 550.1 |
|---|---|
| Abstract Title: | <I>In vivo</I> mapping of the axonal connectivity in cat visual cortex using diffusion tensor MRI. |
| Authors: |
Mori, S.*1
; Ugurbil, K.2
; van Zijl, P.1
; Kim, D. S.2
1Department of Radiology, Johns-Hopkins School of Medicine, Baltimore, 2Center for Magnetic Resonance Research, University of Minnesota Medical School, Minneapolis, |
| Primary Theme and Topics |
F. Sensory Systems - 79. Visual cortex: striate |
| Session: |
550. Visual cortex: striate--maps and imaging II Poster |
| Presentation Time: | Tuesday, November 7, 2000 1:00 PM-2:00 PM |
| Location: | Hall G-J |
| Keywords: | Axonal Connectivity, MRI, Visual Cortex, Diffusion Tensor Imaging |
Magnetic resonance imaging (MRI) provides a unique combination of structural and functional information of the living brain non-invasively, thus yielding information about the where of the brain's information processing. In order to understand, however, also the how of the brain's information processing, it is of central importance to map the pattern of the neuronal connectivity in the same non-invasive manner. In this study, we have utilized the technique of the high-resolution Diffusion Tensor Imaging (DTI) in combination with a 3D fiber reconstruction algorithm to assess the pattern of thalamocortical and cortico-cortical axonal connectivity in cat visual cortex. Cats were initially anesthetized and kept under anesthesia using standard protocols adapted from single unit and optical imaging studies. A surface coil was used. MR experiments were performed on a 4.7-T/31cm (Oxford, UK) horizontal MRI scanner. The MR imaging parameters were: data matrix = 128×64×32; single-shot EPI, FOV = 26 × 26 × 16 mm, TE = 30 ms, and TR = 1s. Diffusion Tensor MRI provides quantitative information on the anisotrophy of water diffusion in cortex, which is indicative for the local directionality of axonal fibers. The apparent diffusion constants were measured along six independent axes, and then combined into a symmetric diffusion tensor. The vector associated with the largest eigenvalue was then assumed to represent the principal direction of the water diffusion in a given voxel. The results of our study suggest that high-resolution mapping of the axonal connectivity in cat visual cortex can be achieved in a non-invasive manner, thus enabling - for the first time - to correlate the pattern of functional activity with that of the underlying neuronal circuitry in a living animal.
Supported by NIH, The Keck Foundation, and the Minnesota Medical Foundation.
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2000 Neuroscience Meeting Planner. New Orleans, LA: Society for Neuroscience, 2000. Online.
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