Paralysed rats walk again!

An interesting new study has revealed that it has been successful in enabling artificially paralysed rats to regain motor function and walk again! These findings have exciting implications for helping humans to recover from spinal damage and Dr. Vissel from the Garvan Institute of Medical Research in Sidney has said that: "we are on the edge of a truly profound advance in modern medicine - the prospect of repairing the spinal cord after injury".

Much of the physiology of the common rat (Rattus norvegicus) is very similar to that of humans, which makes the animal extremely useful for scientific study.

The study, carried out by researchers at the Swiss Federal Institute of Technology (EPFL), involved severing the spinal cord of rats in two separate places at their 7th and 10th thoracic vertebrae (which form the section of your spine behind your ribs). This was sufficient to completely disrupt their voluntary muscle control; leaving the rats paralysed and unable to move. The researchers then injected their spinal cords with a solution of various electrolytes such as serotonin and dopamine receptor agonists, which increased the activity levels of the nerves and stimulated the rats' nerves even further using electricity (at 40Hz if anyone's interested...) by attaching diodes to various segments of their spines near their base.

By supporting the movement of the rats in a robotic harness, researchers found that they were eventually able to walk, run and even climb stairs when their spine was being stimulated! This behaviour was gradually 'built up' however, as the rats appeared to have had to relearn how to move so the research doesn't suggest that there is an 'instant fix' to spinal damage; rather that it is possible with extensive physiotherapy in conjunction with modern medical techniques, such as those used in this experiment.

"It is completely unexpected to see this level of recovery." Professor Courtine (EPFL)

Thus, this exciting experiment suggests that recovery after spinal damage is perfectly possible for humans and that such individuals will eventually be able to live normal and independent lives. Experts point out however that although this technique has worked well in rats, it may not work in humans. 'Real life' injuries to the spine are much more complicated than those that were artificially introduced in this experiment and humans are much larger, more complicated organisms than rats. The study does provide hope however, and, as stated by Dr. Bacon (the director of research at Spinal Research): "this is a robust demonstration that medical research is moving in the right direction and restoring function after paralysis can no longer be dismissed as a pipedream".

Reference

van den Brand R., Heutschi J., Barraud Q., DiGiovanna J., Bartholdi K., Huerlimann M., Friedli L., Vollenweider I., Moraud E. M., Duis S., Dominici N., Micera S., Musienko P. & Courtine G. (2012). Restoring Voluntary Control of Locomotion after Paralyzing Spinal Cord Injury. Science 336, 1182-1185.