1. Characterization of pain-related behaviors in a rat model of acute-to-chronic low back pain: single vs. multi-level disc injury.
- Author
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Barbe, Mary F., Chen, Frank Liu, Loomis, Regina H., Harris, Michele Y., Kim, Brandon M., Xie, Kevin, Hilliard, Brendan A., McGonagle, Elizabeth R., Bailey, Taylor D., Gares, Ryan P., Van Der Bas, Megan, Kalicharan, Betsy A., Holt-Bright, Lewis, Stone, Laura S., Hodges, Paul W., and Klyne, David M.
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BIOLOGICAL models ,CHRONIC pain ,RATS ,INTERVERTEBRAL disk ,PAIN management ,ANIMAL experimentation ,LUMBAR pain - Abstract
Introduction: Low back pain is the most common type of chronic pain. We examined pain-related behaviors across 18 weeks in rats that received injury to one or two lumbar intervertebral discs (IVD) to determine if multi-level disc injuries enhance/prolong pain. Methods: Twenty-three Sprague-Dawley adult female rats were used: 8 received disc puncture (DP) of one lumbar IVD (L5/6, DP-1); 8 received DP of two lumbar IVDs (L4/5 & L5/6, DP-2); 8 underwent sham surgery. Results: DP-2 rats showed local (low back) sensitivity to pressure at 6- and 12- weeks post-injury, and remote sensitivity to pressure (upper thighs) at 12- and 18-weeks and touch (hind paws) at 6, 12 and 18-weeks. DP-1 rats showed local and remote pressure sensitivity at 12-weeks only (and no tactile sensitivity), relative to Sham DP rats. Both DP groups showed reduced distance traveled during gait testing over multiple weeks, compared to pre-injury; only DP-2 rats showed reduced distance relative to Sham DP rats at 12-weeks. DP-2 rats displayed reduced positive interactions with a novel adult female rat at 3-weeks and hesitation and freezing during gait assays from 6-weeks onwards. At study end (18-weeks), radiological and histological analyses revealed reduced disc height and degeneration of punctured IVDs. Serum BDNF and TNFα levels were higher at 18-weeks in DP-2 rats, relative to Sham DP rats, and levels correlated positively with remote sensitivity in hind paws (tactile) and thighs (pressure). Discussion: Thus, multi-level disc injuries resulted in earlier, prolonged and greater discomfort locally and remotely, than single-level disc injury. BDNF and TNFα may have contributing roles. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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