Ferguson, et al. (2001): Stimulation of corticospinal tract regeneration in the chronically injured spinal cord

[Wise Young]

• Ferguson IA, Koide T and Rush RA (2001). Stimulation of corticospinal tract regeneration in the chronically injured spinal cord. Eur J Neurosci. 13 (5): 1059-64. Summary: Acute spinal cord injury models have proved popular in studies aimed at identifying factors capable of influencing axonal regeneration within the central nervous system. In these models, the test factors (e.g. graft tissues or cells, antibodies, growth factors, etc.) are typically administered at the time of spinal cord injury. In this study, we use a rat chronic spinal cord injury model to identify possible factors which can stimulate regeneration of the chronically lesioned corticospinal tract axons. We demonstrate that surgical grafting of segments of autologous, preligated sural nerve, into the syrinx, stimulates sprouting and regeneration of the corticospinal tract as evidenced by the presence of anterograde labelled corticospinal tract processes within the cavity walls two or more weeks after treatment. Regrowing corticospinal processes were not observed within control animals. The anterogradely labelled corticospinal tract axons were found exclusively within the central grey tissue comprising the cavity walls with no regrowing corticospinal process observed within the white matter. A similar pattern of regeneration was observed following injection into the cavity of a suspension of minced autologous preligated sural nerve. Evidence of corticospinal tract regeneration was seen when either wheat germ agglutinin--horseradish peroxidase or biotinylated--dextran was used as an anterograde tracer. These data demonstrate that the chronically injured cortical motor neurons retain the capacity to regenerate for extended periods and that regeneration can be stimulated using grafts of minced, preligated autologous peripheral nerve tissue. <http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?db=m&form=6&dopt=r&uid=11264681> Department of Human Physiology, Flinders University School of Medicine, GPO Box 2100 Adelaide SA 5001 Australia. i.ferguson@flinders.edu.au

[This message was edited by Wise Young on September 23, 2001 at 10:38 PM.]

[Jeff]

What functional recovery was observed? What do they mean by chronic and what was the injury model? This is a great study but such a limited report begs many questions

[Wise Young]

Jeff, I am not sure that they looked at functional recovery in this model. They also seemed to have looked only at the growth into the injury site and not all the way down the spinal cord to the target. The good news is that people are trying. Wise.

[flashfox]

this is a good new for Dr Kao procedure or not?
Sorry for my english

[Wise Young]

flashfox, no problem with your English. I posted this study for several reasons. First, it is a sign of significant effort in Australia to begin doing spinal cord regeneration experiments. Second, it is one of the first reports that I know of growth of corticospinal tracts associated with placing minced pieces of peripheral nerve into the spinal cord.

It does seem to support the efforts by Carl Kao to place pieces of peripheral nerve into the spinal cord. Please note that Mary Bunge had earlier shown that corticospinal tracts will grow into artificial bridges containing Schwann cells. Likewise, Henreich Cheng had shown that corticospinal tracts will grow into peripheral nerve bridges across transection sites of the spinal cord. By the way, when Cheng cuts peripheral nerves to bridge white matter tracts to gray matter. He collects all the little trimmings of the nerve and he mixes them into a bed of fibrin that he puts into the transection site.

In any case, this study did not address the issue of getting the corticospinal tracts to grow all the way past the injury site into the targets below and he also did not report the functional consequences of this procedure.t

[Carl R]

wasn't Dr.Cheng supposed to publish his the results of this work this month? I thought I remember someone saying September.

[Scientific devil's advocate]

To my knowledge, Mary Bunge's group has *not* yet shown widespread regrowth of corticospinal neurons into Schwann cell bridges, certainly without additional treatments with steroids (MP) or neurotrophins............

[Scientific devil's advocate]

And I believe at least two groups have now tried to reproduce Cheng's work but have failed. The surgery certainly sounds difficult to reproduce...........