Functional MRI of the cervical spinal cord during noxious and innocuous thermal stimulation in the α-chloralose- and halothane-anesthetized rat

Lawrence, Jane; Stroman, Patrick W.; Malisza, Krisztina L.

doi:10.1016/j.mri.2007.05.001

« Previous Next »Magnetic Resonance Imaging
Volume 26, Issue 1 , Pages 1-10, January 2008

Functional MRI of the cervical spinal cord during noxious and innocuous thermal stimulation in the α-chloralose- and halothane-anesthetized rat

Jane Lawrence
- Department of Physiology, University of Manitoba, Winnipeg, Manitoba, Canada, R3E 3J7
- Present address: Stanford University School of Medicine, Department of Anesthesia, Stanford Systems Neuroscience and Pain Laboratory, 780 Welch Rd, Suite 208C, Palo Alto, CA 94304-1573, USA.
Patrick W. Stroman
- Department of Physiology, University of Manitoba, Winnipeg, Manitoba, Canada, R3E 3J7
- Department of Diagnostic Radiology, Queens University, Kingston, Ontario, Canada, K7L 2V7
Krisztina L. Malisza
- Department of Physiology, University of Manitoba, Winnipeg, Manitoba, Canada, R3E 3J7
- National Research Council, Institute for Biodiagnostics, Winnipeg, Manitoba, Canada, R3B 1Y6
- Corresponding author. National Research Council of Canada, MR Research and Development, Institute for Biodiagnostics, Winnipeg, Manitoba, Canada R3B 1Y6. Tel.: +1 204 984 6616; fax: +1 204 984 7036.

Received 5 October 2006; received in revised form 30 April 2007; accepted 1 May 2007. published online 25 June 2007.

Abstract

Patterns of neuronal activity in the spinal cord using functional magnetic resonance imaging during noxious (48°C) and innocuous (40°C) thermal stimulation of the rat forepaw were examined. The patterns of functional activity elicited by thermal stimuli were compared in α-chloralose- and halothane-anesthetized rats. Although the locations of active pixels were similar during both types of stimulation, the mean percentage signal change was higher during noxious stimulation in both anesthetic groups. Ipsilateral dorsal horn activity was evident during both noxious and innocuous stimulation in all animals. The greatest consistency of ipsilateral dorsal horn activity occurred at the C3 to C5 spinal cord segments in all groups. Consistent contralateral dorsal horn activity appeared in segments C6 to C8 in all groups. C-fos immunohistochemical staining confirmed the presence of neural activity in the spinal cords of all animals.

Keywords: Functional MRI, Spinal cord, Thermal, Nociception, Anesthesia, C-fos