Feasibility of 3.0 T diffusion-weighted nuclear magnetic resonance imaging in the evaluation of functional recovery of rats with complete spinal cord injury
Study design:Experimental laboratory investigation of hindlimb movement recovery in chronic paraplegic mice.Objectives:Development of an assessment method to discriminatively quantify motor and locomotor-like movements of paraplegic mice.Setting:Laval University Medical Center, Quebec, Canada.Methods:Signs of ‘functional recovery’ were examined in open-field condition during 1 month in adult mice with a complete spinal cord transection at the low-thoracic level.Results:None of the mice exhibited hindlimb movements after spinalization. At 7 days, 33% of them displayed weak nonbilaterally alternating movements (NBA). At 14 days, increased NBA were observed and the first bilaterally alternating movements (BA) in 10% of the mice. A progressive increase of movement frequency and amplitude was found after 2–3 weeks. By the end of the month, 86% displayed mixed NBA and BA. However, none of them recovered the ability to stand or bear their own weight with the hindlimbs.Conclusion:This study reports signs of partial hindlimb movement recovery in chronic paraplegic mice and provides evidence of plasticity in sublesional circuits of neurons occurring in the absence of inputs from the brain, locomotor training or pharmacological treatment. This assessment method can be used to characterize hindlimb movements in complete spinal cord transected mice tested in open-field condition.