Paralyzed rats walk days after nerve reattachment

A salty, calcium-free solution helps reattach severed nerves. Rat patients moved their limbs within minutes after the surgery and up to 70% of leg function were recovered in a month. Video!
Written by Janet Fang, Contributor

Researchers have developed a simple, cheap procedure that repairs nerve damage in the legs. Paralyzed rat patients walked normally within days.

The reduction in recovery time is dramatic: within minutes of waking up in post-op, the rats began to move their damaged limb, and nearly all of them had recovered between 60 to 70% of leg function within 2 to 4 weeks.

The method could be further developed to reattach messy emergency room injuries. New Scientist reports.

After a nerve is severed, the 2 ends should be reconnected as quickly as possible because the disconnected sections wither within a few days.

Usually, doctors stitch the loose ends together, but the body’s own repair mechanism could get in the way. Tiny spheres called vesicles develop in the nerve stumps; these repair each of the 2 cut ends – sometimes sealing the two stumps off, making it hard to connect them later on.

However, if calcium is excluded from the site of the injury, the vesicles don’t form and the damaged nerve ends stay unsealed and in a better state for surgical reattachment.

Utilizing that trait, a team led by George Bittner of the University of Texas at Austin came up with a new procedure.

  1. The injury site is injected with a salty solution, making it a "calcium-free zone."
  2. Then the 2 jagged nerve ends are pulled together so that they’re within a micrometer of each other.
  3. A polymer called polyethylene glycol is then squirted between them. This removes water from the fatty, outer layer of the stumps, allowing the fats to merge together to reconnect the severed ends.
  4. Finally, the natural healing process is restarted by immersing the injury in a salty, calcium-rich solution. This allows the production of vesicles, which repair any remaining gaps in the nerve.

The method has been successfully deployed in 200 trials. Watch a video of the rats here.

The work was published in Journal of Neuroscience Research. From New Scientist.

Image by CowCopTim via Flickr

This post was originally published on Smartplanet.com

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