Tuesday, January 08, 2008

Scientists Able to Get Mice with Spinal Injuries to Walk

Scientists conducting research have been able to gain fresh insights into how partial mobility is possible despite spinal injuries. The research, conducted on mice with spinal injuries could provide a totally different approach to restoring mobility, even if it is partial, in patients who have suffered similar injuries.

Scientists conducting research have been able to gain fresh insights into how partial mobility is possible despite spinal injuries. The research, conducted on mice with spinal injuries could provide a totally different approach to restoring mobility, even if it is partial, in patients who have suffered similar injuries.

In the study, mice were inflicted with spinal injuries in the laboratory. Over a period of two to two and a half months (eight to 10 weeks), the mice were able to walk again, though not as fluently as they used to before the injuries.

The study involving the mice highlighted the fact that after a spinal cord injury, the brain and the spinal cord had the ability to reorganize their functioning and re-establish the communication network needed at the level of the cell to execute the task of walking.

Scientists said after the mice suffered from the partial spinal cord injuries, the neural networks in the brain and the spinal cord reorganized themselves. The reorganization was done in such a way that though the long and continuous neural highways transmitting impulses between the brain and the center for walking located in the lower regions of the spinal cord were broken, the mice were still able to walk.

Researchers are quite excited about the new findings. As Dr. Michael Sofroniew, neurobiology professor at the University of California Los Angeles’ David Geffen School of Medicine and lead researcher put it, “This is not the end of a story. This is the beginning of a story.”

Dr. Sofroniew said the research team was able to identify a mechanism that aided the functionality recovery from partial spinal cord injuries that no one knew about earlier. He said there was still work to be done, and that scientists now could focus on understanding this mechanism better so they would be able to know how to make better use of it.

Dr. Sofroniew said they could achieve this by undertaking the right approach to rehabilitation therapy and also determining how to stimulate this alternative network. The research is almost revolutionary as so long, scientists were of the opinion that the only way to get a person with a spinal cord injury to walk again was to have the long neural highways grow back and connect the brain to the spinal cord base.

The spinal cord basically passes through the neck of a person, down the back. It transmits messages between the brain and the different parts of the body. Any serious injury to the spinal cord, as in a car accident, can sever the long neural highways, causing the patient to be paralyzed. So far, scientists had not been able to cure paralysis of this kind.

The new research shows that when the damage to the spinal cord causes the neural highways to break down and stop messages transmitted from the brain from reaching the designated parts, it was possible for the messages to find alternative ways to reach the destination.

For instance, if the instruction from the brain was to move the leg, as in the case of walking, it would not go over the neural highway; instead, it would travel over an alternate network consisting of a number of shorter connections to ensure the message from the brain reached the legs.

Dr. Sofroniew said the situation was somewhat akin to a traffic situation. If there is a jam on the freeway, one could get on to interconnected and shorter side roads to circumvent the jam and reach the destination. That was how it was in the case of message transmission in the laboratory mice, he said.

During the research, the team shut down half the neural fibers on either side of the spinal cord without disturbing the center. The center has a series of interconnected neural passages to send and receive information between the top and the bottom of the spinal cord.

In the next step, the researchers blocked the short passages as well, and the paralysis came back, confirming the messages had earlier gone to their destination over these shorter networks, which had been earlier left open.

The next step, researchers say, is to find out how to enable the spinal cord nerve cells to develop and grow around a specific injury site so the brain can work with these cells instead and ensure there is no paralysis.

The team of scientists conducting the research has published its work in the journal Nature Medicine.

by Daisy Sarma

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