Functional MRI of the cervical spinal cord during noxious and innocuous thermal stimulation in the alpha-chloralose- and halothane-anesthetized rat.
Patterns of neuronal activity in the spinal cord using functional magnetic resonance imaging during noxious (48 degrees C) and innocuous (40 degrees C) thermal stimulation of the rat forepaw were examined. The patterns of functional activity elicited by thermal stimuli were compared in alpha-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.
Lawrence
Jane
J
Department of Physiology, University of Manitoba, Winnipeg, Manitoba, Canada, R3E 3J7.
Stroman
Patrick W
PW
Malisza
Krisztina L
KL
D018685:Anesthetics, Inhalation / Q000494:pharmacology; D018686:Anesthetics, Intravenous / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001831:Body Temperature; D002245:Carbon Dioxide / Q000097:blood; D002574:Cervical Vertebrae; D002698:Chloralose / Q000494:pharmacology*; D004558:Electric Stimulation; D005552:Forelimb / Q000294:innervation; D006221:Halothane / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects; D007150:Immunohistochemistry; D008279:Magnetic Resonance Imaging / Q000379:methods*; D010100:Oxygen / Q000097:blood; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000502:physiology*
D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D002245:Carbon Dioxide; D002698:Chloralose; D010100:Oxygen; D006221:Halothane