• Neuroscience · Jan 2006

    Acute implantation of an avulsed lumbosacral ventral root into the rat conus medullaris promotes neuroprotection and graft reinnervation by autonomic and motor neurons.

    • T X Hoang, J H Nieto, B H Dobkin, N J K Tillakaratne, and L A Havton.
    • Department of Neurology and Brain Research Institute, David Geffen School of Medicine at UCLA, 710 Westwood Plaza, Los Angeles, CA 90095-1769, USA.
    • Neuroscience. 2006 Jan 1;138(4):1149-60.

    AbstractTrauma to the conus medullaris and cauda equina may result in autonomic, sensory, and motor dysfunctions. We have previously developed a rat model of cauda equina injury, where a lumbosacral ventral root avulsion resulted in a progressive and parallel death of motoneurons and preganglionic parasympathetic neurons, which are important for i.e. bladder control. Here, we report that an acute implantation of an avulsed ventral root into the rat conus medullaris protects preganglionic parasympathetic neurons and motoneurons from cell death as well as promotes axonal regeneration into the implanted root at 6 weeks post-implantation. Implantation resulted in survival of 44+/-4% of preganglionic parasympathetic neurons and 44+/-4% of motoneurons compared with 22% of preganglionic parasympathetic neurons and 16% of motoneurons after avulsion alone. Retrograde labeling from the implanted root at 6 weeks showed that 53+/-13% of surviving preganglionic parasympathetic neurons and 64+/-14% of surviving motoneurons reinnervated the graft. Implantation prevented injury-induced atrophy of preganglionic parasympathetic neurons and reduced atrophy of motoneurons. Light and electron microscopic studies of the implanted ventral roots demonstrated a large number of both myelinated axons (79+/-13% of the number of myelinated axons in corresponding control ventral roots) and unmyelinated axons. Although the diameter of myelinated axons in the implanted roots was significantly smaller than that of control roots, the degree of myelination was appropriate for the axonal size, suggesting normal conduction properties. Our results show that preganglionic parasympathetic neurons have the same ability as motoneurons to survive and reinnervate implanted roots, a prerequisite for successful therapeutic strategies for autonomic control in selected patients with acute conus medullaris and cauda equina injuries.

      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…