New Methods Could Speed Up Repair Of Injured Nerves
URL: http://www.npr.org/blogs/health/2012/02/27/147344516/new-methods-could-speed-up-repair-of-injured-nervesAuthor: Jon Hamilton
Date of Publication: 27 February 2012
New Methods Could Speed Up Repair of Injured Nerves
Summary:
Recently, there have been studies done with rats regarding the healing of injured nerves. The goal of the studies has been to find a way to repair nerves faster, in a matter of days instead of months. So far, the studies have focused on nerves in the legs, but scientists hope to extend their focus to spinal injuries eventually. Research has mostly been on peripheral nerves. According to one scientist, many people damage their peripheral nerves by a kitchen accident, making these kinds of injuries fairly common. But, nerves do not heal like most other body parts. For nerve damage, the nerve mechanism itself stays alive between the brain and injury while the tissues and other things die. The body then cleans the nerve tube and opens it up so that a new nerve can grow from the point where the injury occurred. The new nerve grows slowly, only about 1-2 mm per day. This is a serious issue if someone for example cuts a nerve in their shoulder that controls their fingers, as the nerve will take a long time to heal completely. And, even then it may be too late and the muscle will not be able to be revived. Lone Star Paralysis has come up with a way to speed up this process, however. The idea is to patch together the two severed halves of the nerve. They do this with a multiple step process in which the nerve is exposed at first. Then, chemical compounds are used that reverse the sealing of the nerve ends. The nerve halves are drawn together and chemically reattached. The chemicals used in this process have already been approved for use in humans. They have been tested to work in rats. In the studies that have been done so far with rats, a nerve in the upper thigh has been severed. This nerve controls the legs, paws, and toes. After treatment, the results have been fabulous and the rats get better as soon as they recover from the surgery. Other scientists have tried to fuse nerves with material from crustacean shells. Overall, the idea of this research is to get the procedures to work well on peripheral nerves so that spinal nerve injuries can be healed in the future.
Description of Relevance:
This media relates to our study of the nervous system from this term. We have learned how the nerves of the nervous system transmit signals in our body and how important this is, as is also mentioned by the media. This makes it clear how much it would help if nerve injuries could be healed faster. Furthermore, we have learned about the peripheral and central nervous systems. In this media, it is stated that research has been done with the peripheral nervous system in hopes that it can be applied to spinal injuries, which are related to the central nervous system. We learned that the central nervous system controls many vital functions of the body, making these injuries very dangerous. Also, the fact that tests have been done with rats but applied to humans is similar to the rate dissection that we did this term. We also used rats to explore concepts related to the human body. Overall, this media relates to our study of the nervous system and to our use of rats as models of the human body.
By Helen Stone
How is a damaged nerve healed? Do other structures in the body help it recover?
ReplyDeleteAs of now, only PNS nerves can be healed. The nerves in the CNS cannot regrow, or at least not by the body alone. Nerves can be damaged in several different ways, so they are also healed differently depending upon the damage. For example, sometimes the nerve fibers are severed while the myelin sheath remains intact. In this case, the nerve fibers farthest from the brain die and eventually regrow slowly inside the sheath.
DeleteIn my research, I did not turn up anything about the exact processes by which nerves heal. However, it seems that people have discovered many treatments to aid in the healing of damaged nerves. For example, it is suggested to take a B12 supplement as this helps the myelin sheath to regrow. This leads me to believe that the myelin sheath has an important function in the regrowth of nerves. Overall, I would guess that nerves regrow like any other body structure. Based on their particular structure, I would imagine that when the myelin sheath rebuilds the axon can regrow inside of it. As far as I could tell from my research, it seems that CNS nerves do not regrow because substances in the body actually inhibit them to regrow. This is because the CNS is so complicated that the risk of regrowth being in error is too high. I did not find any research to suggest that other structures help nerves to recover. This link has some interesting information about why the CNS does not regrow: http://biomed.brown.edu/Courses/BI108/BI108_2001_Groups/Nerve_Regeneration/Introduction/Introduction.htm
Also, when a nerve is damaged the body clears out the damaged tissues to make way for new nerve growth. Usually nerves are severed into two ends, so the two "stubs" regrow towards each other. The process is quite slow and often the nerve and its target are far apart. This is why new techniques are being developed to speed up nerve growth.
DeleteWhy have they focused primarily on the legs in their studies? Is there a reason that they get better results when testing on the legs?
ReplyDeleteLegs have been focused on because they are part of the PNS. As was discussed above, PNS nerves can be healed while as of yet CNS nerves cannot be healed. This is because the body inhibits the regrowth of CNS nerves. So, legs are a large and easily tested structure whose nerves are part of the PNS. I did not find any information to suggest that legs are particularly special when it comes to nerves. But, I think that since rats were being tested legs were a logical choice. They don't have arms obviously and the only other part of the PNS would be their tails. Also, the part of the upper thigh that is cut controls the paw, lower leg, etc., so it would be easier to determine if the nerve healed as these are easily observable structures.
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