Neuroscience 2004 Abstract
| Presentation Number: | 693.8 |
|---|---|
| Abstract Title: | Functional magnetic resonance imaging studies in alert, behaving primates at 4.7T. |
| Authors: |
Bolding, M.*1
; Ward, M. K.1
; Twieg, D.1
; Mays, L. E.2
; Weller, R. E.1
; Walsh, E. G.1
; Gawne, T. J.1
; Dobbins, A. C.1
; Busettini, C.1
; Gamlin, P. D.1
1Ctr. for the Develop. of Functional Imaging, UAB, Birmingham, AL 2NC, 924 18th Street South, 35294, |
| Primary Theme and Topics |
Techniques in Neuroscience - Staining, tracing and imaging techniques |
| Session: |
693. Imaging Techniques: fMRI and Other Poster |
| Presentation Time: | Tuesday, October 26, 2004 11:00 AM-12:00 PM |
| Location: | San Diego Convention Center - Hall A-H, Board # FFF17 |
| Keywords: |
Although significant strides have been made using high-field fMRI to study brain activity in primates (e.g. Logothetis, 2003, 2002), many of these studies have employed anesthesia and paralytics which can significantly affect the BOLD response (Leopold et al., 2002). To better approximate the conditions under which human data is collected and to conduct oculomotor studies, we have recently developed techniques to acquire fMRI data at 4.7T using alert, behaving rhesus monkeys.
To optimize ergonomics, a 60-cm bore, vertically oriented, superconducting magnet (Magnex) with a Varian console is used. Head stabilization is achieved through a stereotaxically-placed, polyetheretherketon superstructure attached to the skull with MRI-compatible ceramic screws. Monkeys are trained to fixate and/or track targets on a visual display system (Avotec) while the position of each eye is monitored (SensorMotoric Instruments). A successive approximation training schedule is then used to acclimate the animals to the environment that they encounter in the magnet, including the use of sound-attenuating foam to limit noise exposure and to minimize ear motion. After training, animals perform well during fMRI acquisition sessions.
In our preliminary studies, we have acquired structural images with gradient-echo sequences (T1 weighted, TE/TR: 20/2000ms, FOV: 128mm², matrix: 256 x 256, thickness: 1mm). In addition, using EPI sequences (TE/TR: 30/2000ms, FA: 90°, FOV: 128mm², matrix: 64 x 64), we are able to show BOLD functional activation of striate and extrastriate visual cortex in response to visual stimuli.
These results show that with appropriate training and sequence parameters functional MRI data can be obtained at 4.7T from alert, behaving monkeys.
To optimize ergonomics, a 60-cm bore, vertically oriented, superconducting magnet (Magnex) with a Varian console is used. Head stabilization is achieved through a stereotaxically-placed, polyetheretherketon superstructure attached to the skull with MRI-compatible ceramic screws. Monkeys are trained to fixate and/or track targets on a visual display system (Avotec) while the position of each eye is monitored (SensorMotoric Instruments). A successive approximation training schedule is then used to acclimate the animals to the environment that they encounter in the magnet, including the use of sound-attenuating foam to limit noise exposure and to minimize ear motion. After training, animals perform well during fMRI acquisition sessions.
In our preliminary studies, we have acquired structural images with gradient-echo sequences (T1 weighted, TE/TR: 20/2000ms, FOV: 128mm², matrix: 256 x 256, thickness: 1mm). In addition, using EPI sequences (TE/TR: 30/2000ms, FA: 90°, FOV: 128mm², matrix: 64 x 64), we are able to show BOLD functional activation of striate and extrastriate visual cortex in response to visual stimuli.
These results show that with appropriate training and sequence parameters functional MRI data can be obtained at 4.7T from alert, behaving monkeys.
Supported by EB003292, W.M. Keck Foundation, EY13753, NSF0116467, EY07558
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2004 Neuroscience Meeting Planner. San Diego, CA: Society for Neuroscience, 2004. Online.
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