Spinal injuries can have irreversible effects
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Doctors hope to use the body's
own nerves to bridge the gap in the spinal cord left by
paralysing injuries.
Marie Filbin, from the City University of New York, took a
nerve leaving the spine just above an injury, and reattached it
below.
New Scientist magazine reports that rats used in the
experiment showed some signs of renewed movement.
A UK expert said the injury location could govern whether a
suitable nerve was available for surgery.
An injury that breaks or severely damages the spinal cord can
cause permanent disability, with the extent set by exactly how
far down the spine the damage has happened.
Scientists are hunting for ways to repair that damage,
including using growth-promoting chemicals to encourage healing
across the 'gap', and grafts of nerve fibres from elsewhere in
the body.
The New York approach is slightly different - it takes one of
the nerves that naturally leaves the spinal column, disconnects
it from its destination, then plugs it back into the spinal cord
using a protein "glue".
In the case of the rats, this was a nerve heading for the
abdominal muscles, which was taken just above a break in the
spinal cord, and reattached below.
After just two weeks, it became clear that the new
arrangement was working, with the nerve growing and starting to
form connections with its new neighbour.
Sending electrical impulses down the spinal cord caused
twitching in the lower limbs, again indicating that connections
had been made.
There were no ill-effects in the abdominal muscle, as other
nerves connected to it compensated for the loss of one
connection.
Hard job
Dr Filbin told New Scientist: "It's amazing that the nerve
bridge makes functional synapses and regenerates to the state it
does."
She warned, however, that it might not be possible for the
abdominal nerve to upgrade from its more modest job to take on
the sophisticated role of the spinal cord.
Professor Giorgio Terenghi, from the University of
Manchester, said that the approach was very interesting, and
avoided some of the pitfalls of other nerve grafting techniques.
"It's a very good idea, but the key thing is how much
function they will be able to restore using this technique."
He said that another issue was that while the position of the
spinal cord injury in the rats suited the use of the abdominal
nerve, if the injury was elsewhere, higher or lower, there might
not be a nerve that could be readily "sacrificed" to form the
link without creating other problems.
"You don't want to rob Peter to pay Paul," he said.
It's a very good idea, but the key thing is
how much function they will be able to restore
using this technique
