Featured Research

from universities, journals, and other organizations

Researchers Splice Severed Spinal Cords

Date:
November 13, 1998
Source:
Purdue University
Summary:
Purdue University researchers have for the first time restored electrical nerve impulses in the severed spinal cord of a mammal.

Purdue University researchers have for the first time restored electrical nerve impulses in the severed spinal cord of a mammal.

The scientists conducted their experiments on isolated spinal cords removed from adult guinea pigs. Researchers fused the cut nerve fibers using a polymer called PEG. Electrical impulses were restored in all of the guinea pig cords used in the study. The repaired spinal cords transmitted between 5 percent and 58 percent of pre-cut impulses.

Significant numbers, but not all, of the nerve fibers within the cut spinal cords were reconnected. Researchers demonstrated this by passing special dyes through the repaired nerve fibers.

"If you have even 5 percent of the nerve fibers carrying nerve impulses, you'll get significantly more than 5 percent back in terms of restored behavior," says Richard B. Borgens, professor of developmental anatomy at Purdue. He and his colleague, assistant professor Dr. Riyi Shi, both of Purdue's Center for Paralysis Research in the School of Veterinary Medicine, will report their findings Thursday (11/12) in Long Beach, Calif., at the 18th annual meeting of the Society for Physical Regulation in Biology and Medicine. Borgens also has submitted a paper on the research to the Journal of Neurotrauma.

"This technique may be a revolutionary new way of dealing with injuries to the nervous system," Borgens says. "It's too soon to know whether it would help patients with old injuries, but it is likely to be useful in treating recent injuries."

Shi and Borgens now are testing the procedure in live animals. They plan to conduct clinical trials in natural cases of paraplegia in dogs early in 1999, but human clinical trials are at least two years away.

The isolated spinal cords remain viable for about 36 hours after removal. Borgens says the results of studies in live animals will shed more light on how permanent the new technique might be.

Borgens and Shi applied polyethylene glycol, or PEG -- a nontoxic, water-soluble polymer used in medicine and cosmetics -- across the region of the guinea pig's spinal cord that had been severed but gently pressed back together. PEG was applied for two minutes, then removed. The polymer "fused" the membranes of a significant number of nerve cells together, making them continuous once again.

Using an apparatus and procedure that Shi designed, the researchers then applied a small electrical current to one end of the cord to stimulate nerve impulses to travel towards the other end. Between five and 15 minutes after the PEG application, nerve fibers were repaired, allowing some impulses to reach the other end of the severed cord in 100 percent of the cases.

"The technique is called fusion technology," Borgens explains. He compares the procedure to repairing a garden hose -- the rubber is the cell membrane and the water inside is the salty material, called cytoplasm, found inside all cells. "If we cut the hose and just hold the two ends tightly together, they're not going to reconnect or function as a hose. But if we add this special molecule, PEG, the 'rubber' melts a tiny bit on each side and literally fuses the 'hose' back together."

Borgens says the technique also can repair crushed nerve cells that develop holes in their membranes.

"In most spinal cord injuries in animals and in people, the spinal cord is not completely severed, as we have done in these first experiments," he says. "The cord is more likely to be crushed, and the nerve fibers develop holes in their membranes, which ultimately leads to separation of the nerve fiber within 24 to 72 hours."

Nerve cells consist of a cell body and trailing tail called an axon, which can extend from the spinal cord to the muscles in the leg, for example.

In mammals, if nerve fibers outside the brain and spinal cord are damaged, they can regenerate and may eventually reach their original target muscle to restore some function. Spinal cord and brain nerve axons, however, do not regenerate in mammals, and once separated from the cell body, they die. The result is paralysis.

Borgens and his colleagues at the Center for Paralysis Research have done extensive work in producing other methods to treat naturally paralyzed dogs with spinal cord injuries, and some methods have moved to tests in human spinal cord injuries.

Borgens' research is supported in part by the Department of Defense and the National Science Foundation.


Story Source:

The above story is based on materials provided by Purdue University. Note: Materials may be edited for content and length.


Cite This Page:

Purdue University. "Researchers Splice Severed Spinal Cords." ScienceDaily. ScienceDaily, 13 November 1998. <www.sciencedaily.com/releases/1998/11/981113082450.htm>.
Purdue University. (1998, November 13). Researchers Splice Severed Spinal Cords. ScienceDaily. Retrieved September 3, 2014 from www.sciencedaily.com/releases/1998/11/981113082450.htm
Purdue University. "Researchers Splice Severed Spinal Cords." ScienceDaily. www.sciencedaily.com/releases/1998/11/981113082450.htm (accessed September 3, 2014).

Share This



More Health & Medicine News

Wednesday, September 3, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Snack Attack: Study Says Action Movies Make You Snack More

Snack Attack: Study Says Action Movies Make You Snack More

Newsy (Sep. 2, 2014) You're more likely to gain weight while watching action flicks than you are watching other types of programming, says a new study published in JAMA. Video provided by Newsy
Powered by NewsLook.com
U.N. Says Ebola Travel Restrictions Will Cause Food Shortage

U.N. Says Ebola Travel Restrictions Will Cause Food Shortage

Newsy (Sep. 2, 2014) The U.N. says the problem is two-fold — quarantine zones and travel restrictions are limiting the movement of both people and food. Video provided by Newsy
Powered by NewsLook.com
Doctors Fear They're Losing Battle Against Ebola

Doctors Fear They're Losing Battle Against Ebola

AP (Sep. 2, 2014) As a third American missionary is confirmed to have contracted Ebola in Liberia, doctors on the ground in West Africa fear they're losing the battle against the outbreak. (Sept. 2) Video provided by AP
Powered by NewsLook.com
Tech Giants Bet on 3D Headsets for Gaming, Healthcare

Tech Giants Bet on 3D Headsets for Gaming, Healthcare

AFP (Sep. 2, 2014) When Facebook acquired the virtual reality hardware developer Oculus VR in March for $2 billion, CEO Mark Zuckerberg hailed the firm's technology as "a new communication platform." Duration: 02:24 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins