Magali Millecamps1,2, Seunghwan Lee3,4, Daniel Z Foster3,4, Laura S Stone3,4,5,6. 1. Faculty of Dentistry, McGill University, Montreal, QC, Canada. Magali.millecamps@mcgill.ca. 2. The Alan Edwards Centre for Research On Pain, McGill University, 740 Dr. Penfield Ave, suite 3200, Montreal, QC, H3A 0G1, Canada. Magali.millecamps@mcgill.ca. 3. Faculty of Dentistry, McGill University, Montreal, QC, Canada. 4. The Alan Edwards Centre for Research On Pain, McGill University, 740 Dr. Penfield Ave, suite 3200, Montreal, QC, H3A 0G1, Canada. 5. Departments of Anesthesiology, Pharmacology & Therapeutics, Neurology & Neurosurgery, Faculty of Medicine, McGill University, Montreal, QC, Canada. 6. Department of Anesthesiology, University of Minnesota, Minneapolis, USA.
Abstract
STUDY DESIGN: A multi-cohort, case-control rodent study. PURPOSE: Investigate the long-term behavioural, histologic and radiologic consequences on the complete lumbar spine of L4/5 intervertebral disc (IVD) injury in mice and determine if increased physical activity mitigates the observed changes. METHODS: Cohorts of 2-month-old CD1 female mice underwent a single ventral puncture of the L4/5 IVD. 0.5-, 3- or 12-months after injury, general health (body weight and locomotor capacity), behavioural signs of axial discomfort (tail suspension, grip strength and FlexMaze assays) and radiating pain (von Frey and acetone tests) were assessed. Experimental groups with free access to an activity wheel in their home cages were including in the 12-month cohort. Lumbar disc status was determined using colorimetric staining and radiologic (X-ray and T2-MRI) analysis. Innervation was measured by immunoreactivity for PGP9.5 and calcitonin gene-related peptide. RESULTS: No changes in general health or persistent signs of axial discomfort were observed up to one year post-injury. In contrast, signs of radiating pain developed in injured mice at 3 months post-injury, persisted up to 12 months and were reversed by long-term physical activity. At 12-months post-injury, degeneration was observed in non-injured lumbar discs. Secondary degenerating IVDs were similar to the injured discs by X-ray (narrowing) and T2-MRI (internal disc disruption) but did not show abnormal innervation. Increased physical activity had no impact on mechanically injured IVDs, but attenuated disc narrowing at other lumbar levels. CONCLUSIONS: Mechanical injury of L4/5-IVDs induces delayed radiating pain and degeneration of adjacent discs; increased physical activity positively mitigated both.
STUDY DESIGN: A multi-cohort, case-control rodent study. PURPOSE: Investigate the long-term behavioural, histologic and radiologic consequences on the complete lumbar spine of L4/5 intervertebral disc (IVD) injury in mice and determine if increased physical activity mitigates the observed changes. METHODS: Cohorts of 2-month-old CD1 female mice underwent a single ventral puncture of the L4/5 IVD. 0.5-, 3- or 12-months after injury, general health (body weight and locomotor capacity), behavioural signs of axial discomfort (tail suspension, grip strength and FlexMaze assays) and radiating pain (von Frey and acetone tests) were assessed. Experimental groups with free access to an activity wheel in their home cages were including in the 12-month cohort. Lumbar disc status was determined using colorimetric staining and radiologic (X-ray and T2-MRI) analysis. Innervation was measured by immunoreactivity for PGP9.5 and calcitonin gene-related peptide. RESULTS: No changes in general health or persistent signs of axial discomfort were observed up to one year post-injury. In contrast, signs of radiating pain developed in injured mice at 3 months post-injury, persisted up to 12 months and were reversed by long-term physical activity. At 12-months post-injury, degeneration was observed in non-injured lumbar discs. Secondary degenerating IVDs were similar to the injured discs by X-ray (narrowing) and T2-MRI (internal disc disruption) but did not show abnormal innervation. Increased physical activity had no impact on mechanically injured IVDs, but attenuated disc narrowing at other lumbar levels. CONCLUSIONS: Mechanical injury of L4/5-IVDs induces delayed radiating pain and degeneration of adjacent discs; increased physical activity positively mitigated both.
Authors: Kyle D Allen; Timothy M Griffin; Ramona M Rodriguiz; William C Wetsel; Virginia B Kraus; Janet L Huebner; Lawrence M Boyd; Lori A Setton Journal: Arthritis Rheum Date: 2009-09
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Authors: Changgui Shi; Sujun Qiu; Scott M Riester; Vaskar Das; Bingqian Zhu; Atiyayein A Wallace; Andre J van Wijnen; Fackson Mwale; James C Iatridis; Daisuke Sakai; Gina Votta-Velis; Wen Yuan; Hee-Jeong Im Journal: J Orthop Res Date: 2018-03-14 Impact factor: 3.494