Isoflurane anesthesia does not affect spinal cord neurovascular coupling: evidence from decerebrated rats
Neurological examination remains the primary clinical investigation in patients with spinal cord injury. However, neuroimaging methods such as functional magnetic resonance imaging (fMRI) are promising tools for following functional changes in the course of injury, disease and rehabilitation. However, the relationship between neuronal activity and blood flow in the spinal cord on which fMRI relies has been largely overlooked. The objective of this study was to examine neurovascular coupling in the spinal cord of decerebrated rats during electrical stimulation of the sciatic nerve with and without isoflurane anesthesia (1.2%). Local field potentials (LFP) and spinal cord blood flow (SCBF) were recorded simultaneously in the lumbosacral enlargement. Isoflurane did not significantly alter LFP (p = 0.53) and SCBF (p = 0.57) amplitude. Accordingly, neurovascular coupling remained comparable with or without isoflurane anesthesia (p = 0.39). These results support the use of isoflurane in rodents to investigate nociceptive functions of the spinal cord using fMRI.
KeywordsSpinal cord Neurovascular coupling Pain Nociception Blood flow Local field potential
This project was funded by the Natural Science and Engineering Research Council (NSERC) of Canada (Grant Numbers: 402176 (MP); 05403 (HL)). TP was supported by scholarships from the NSERC, the department of anatomy (UQTR) and the “Fonds de Recherche du Québec en Santé” (FRQS). The contribution of Mathieu Piché was supported by the UQTR research chair in pain neurophysiology, the “Fondation de Recherche en Chiropratique du Québec” and the FRQS.
TP contributed to all aspects of the research. HL contributed to all aspects of the research. MP contributed to all aspects of the research and obtained funding for the study.
This study was supported by a grant from the Natural Sciences and Engineering Research Council of Canada (Grant Numbers: 402176 (MP); 05403 (HL)).
Compliance with ethical standards
Conflict of interest
Thierry Paquette reports no financial or other relationship that may lead to any conflict of interest. Hugues Leblond reports no financial or other relationship that may lead to any conflict of interest. Mathieu Piché reports no financial or other relationship that may lead to any conflict of interest.
All experiments followed “Guiding Principles for the Care and Use of Animals in the Field of Physiological Sciences” and were approved by the animal care committee of Université du Québec à Trois-Rivières, in accordance with the Canadian Council on Animal Care.
- 1.Wheeler-Kingshott CA, Stroman PW, Schwab JM, Bacon M, Bosma R, Brooks J, Cadotte DW, Carlstedt T, Ciccarelli O, Cohen-Adad J, Curt A, Evangelou N, Fehlings MG, Filippi M, Kelley BJ, Kollias S, Mackay A, Porro CA, Smith S, Strittmatter SM, Summers P, Thompson AJ, Tracey I (2014) The current state-of-the-art of spinal cord imaging: applications. Neuroimage 84:1082–1093CrossRefGoogle Scholar