• Journal of neurotrauma · Feb 2011

    Activity-dependent increase in neurotrophic factors is associated with an enhanced modulation of spinal reflexes after spinal cord injury.

    • Marie-Pascale Côté, Gregory A Azzam, Michel A Lemay, Victoria Zhukareva, and John D Houlé.
    • Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, Pennsylvania 19129, USA.
    • J. Neurotrauma. 2011 Feb 1;28(2):299-309.

    AbstractActivity-based therapies such as passive bicycling and step-training on a treadmill contribute to motor recovery after spinal cord injury (SCI), leading to a greater number of steps performed, improved gait kinematics, recovery of phase-dependent modulation of spinal reflexes, and prevention of decrease in muscle mass. Both tasks consist of alternating movements that rhythmically stretch and shorten hindlimb muscles. However, the paralyzed hindlimbs are passively moved by a motorized apparatus during bike-training, whereas locomotor movements during step-training are generated by spinal networks triggered by afferent feedback. Our objective was to compare the task-dependent effect of bike- and step-training after SCI on physiological measures of spinal cord plasticity in relation to changes in levels of neurotrophic factors. Thirty adult female Sprague-Dawley rats underwent complete spinal transection at a low thoracic level (T12). The rats were assigned to one of three groups: bike-training, step-training, or no training. The exercise regimen consisted of 15 min/d, 5 days/week, for 4 weeks, beginning 5 days after SCI. During a terminal experiment, H-reflexes were recorded from interosseus foot muscles following stimulation of the tibial nerve at 0.3, 5, or 10 Hz. The animals were sacrificed and the spinal cords were harvested for Western blot analysis of the expression of neurotrophic factors in the lumbar spinal cord. We provide evidence that bike- and step-training significantly increase the levels of brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and NT-4 in the lumbar enlargement of SCI rats, whereas only step-training increased glial cell-derived neurotrophic factor (GDNF) levels. An increase in neurotrophic factor protein levels that positively correlated with the recovery of H-reflex frequency-dependent depression suggests a role for neurotrophic factors in reflex normalization.

      Pubmed     Full text   Copy Citation     Plaintext  

      Add institutional full text...

    Notes

     
    Knowledge, pearl, summary or comment to share?
    300 characters remaining
    help        
    You can also include formatting, links, images and footnotes in your notes
    • Simple formatting can be added to notes, such as *italics*, _underline_ or **bold**.
    • Superscript can be denoted by <sup>text</sup> and subscript <sub>text</sub>.
    • Numbered or bulleted lists can be created using either numbered lines 1. 2. 3., hyphens - or asterisks *.
    • Links can be included with: [my link to pubmed](http://pubmed.com)
    • Images can be included with: ![alt text](https://bestmedicaljournal.com/study_graph.jpg "Image Title Text")
    • For footnotes use [^1](This is a footnote.) inline.
    • Or use an inline reference [^1] to refer to a longer footnote elseweher in the document [^1]: This is a long footnote..

    hide…