Neuroscience 2004 Abstract
| Presentation Number: | 747.12 |
|---|---|
| Abstract Title: | Functional magnetic resonance imaging studies of noxious-evoked brain activation in anaesthetized rats. |
| Authors: |
Governo, R. J. M.*1
; Shah, Y. B.1,2
; Prior, M. J. W.2
; Marsden, C. A.1
; Morris, P. G.2
; Chapman, V.1
1Sch. Biomed. Sci., Queens Med. Centre, Nottingham, United Kingdom 2United Kingdom, University of Nottingham, NG7 2UH, |
| Primary Theme and Topics |
Sensory Systems - Pain -- Pain Models |
| Secondary Theme and Topics | Sensory Systems<br />- Pain<br />-- Treatments for persistent pain |
| Session: |
747. Inflammatory Pain: Pathophysiology II Poster |
| Presentation Time: | Tuesday, October 26, 2004 4:00 PM-5:00 PM |
| Location: | San Diego Convention Center - Hall A-H, Board # P22 |
| Keywords: | capsaicin, fMRI, BOLD, pain |
Intraplantar injection of capsaicin produces primary and secondary hyperalgesia, modelling some of the symptoms associated with persistent pain states. Previous functional magnetic resonance imaging (fMRI) studies of Blood Oxygen Level Dependent (BOLD) haemodynamic responses have demonstrated nociceptive-evoked activation of the brain (Malisza and Docherty, 2001). Here, T2-weighted BOLD-contrast fMRI was used to study the time course of capsaicin-evoked BOLD responses in halothane anaesthetised rats (Shah et al., 2004). Rapid Acquisition Relaxation Enhanced (RARE) sequence data was obtained from a continuous scan comprising of 12 basal volume sets, each collected every 4 min 40sec, followed by intradermal injection of capsaicin (30µg/5µl saline with 7% Tween 80, n=8) and a further collection of 18 volume sets. Data were analysed using SPM99 (random effects analysis, p<0.05). Capsaicin-evoked significant increases in BOLD response in the nucleus accumbens (T=6.81, p<0.05), ventral-medial thalamic nuclei (T=7.82, p=0.01) and PAG (T=5.02, p<0.05), with maximal values of 1.15±0.15%, 1.11±0.07% and 1.21±0.16% post-injection respectively. Maximal effects of capsaicin were observed 10-15 minutes post injection. These data indicate that fMRI studies of capsaicin-evoked brain activation are a useful approach for the study of CNS responses to hyperalgesia.
Malisza KL, Docherty JC (2001) Capsaicin as a source for painful stimulation in functional MRI. J Magn Reson Imaging 14: 341-347.
Shah YB, Prior MJ, Dixon AL, Morris PG, Marsden CA (2004) Detection of cannabinoid agonist evoked increase in BOLD contrast in rats using functional magnetic resonance imaging. Neuropharmacology 46: 379-387.
Malisza KL, Docherty JC (2001) Capsaicin as a source for painful stimulation in functional MRI. J Magn Reson Imaging 14: 341-347.
Shah YB, Prior MJ, Dixon AL, Morris PG, Marsden CA (2004) Detection of cannabinoid agonist evoked increase in BOLD contrast in rats using functional magnetic resonance imaging. Neuropharmacology 46: 379-387.
Supported by Work supported by Pfizer
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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