Translation of the rat thoracic contusion model; Part 1 - Supraspinally versus spinally mediated pain-like responses and spasticity
(2014) Spinal Cord — Vol. 52, n° 7, p. 524-528 (2014)
Files
No attached file found for this publication.
Details
- Authors
- Abstract
- Study design: Experimental animal study.Objectives: Stimulus-evoked below-level paw withdrawals in animal models of spinal cord injury (SCI) can be mediated solely by below-level spinal cord reflexes. Interpreting lowered thresholds for such responses as a model for chronic below-level pain after (thoracic contusion) SCI appears not appropriate, which requires reinterpretation of many prior results. However, how to reinterpret the changes in withdrawal thresholds and what can be a better alternative for pain/sensory assessments remains unclear.Setting: University of California, San Diego.Methods: We introduce a method using supraspinally mediated escape responses to assess pain-like sensitivity thresholds on a continuous/linear scale. To further understand the decrease in hindpaw withdrawal thresholds, we investigated whether they may be interpreted as spasticity.Results:The escape response test can be used to assess SCI-induced changes in below-level sensory thresholds. These thresholds were found to increase soon after moderate or severe SCI, while, in parallel, hindpaw withdrawal thresholds decreased. However, the latter did not co-occur with spasticity, suggesting that SCI-induced increased withdrawal responses are probably best interpreted as a form of hyperreflexia with pathophysiological analogies of spasms and/or clonus, or a species-specific phenomenon.Conclusion:Decreased below-level withdrawal thresholds do not reflect pain-like hypersensitivity in rodent models of (thoracic contusion) SCI. A large body of previous preclinical SCI pain research needs reinterpretation. We actually found below-level thermal and mechanical hypoesthesia and we also excluded a relation between withdrawal hyperreflexia and spasticity. Withdrawal hyperreflexia might still prove useful to model spasms or clonus, which are, like hypoesthesia, also significant clinical problems after SCI. © 2014 International Spinal Cord Society.
- Affiliations
Citations
van Gorp, S., Marsala, M., Joosten, E. A., Nguyen, S., Leerink, M., & Deumens, R. (2014). Translation of the rat thoracic contusion model; Part 1 - Supraspinally versus spinally mediated pain-like responses and spasticity. Spinal Cord, 52(7), 524-528. https://doi.org/10.1038/sc.2014.72 (Original work published 2014)