Researchers have discovered that an active lifestyle on a daily basis can increase the chances of regenerating damaged nerve fibres in the event of spinal cord injury. They even developed a drug from a protein released into the body through this good habit to promote a more complete recovery.
The advantages of sport are no longer to be proven, because in addition to maintaining a healthy weight, it helps to regulate sleep, contributes to hormonal balance and muscle tone, not to mention the essential maintenance of the cardiovascular system. Researchers at Imperial College London say that regular physical activity also has beneficial effects on a part of the body that has not yet been given much attention: the spinal cord. Housed in the spine, this part of the central nervous system plays a role as a nerve centre responsible for certain reflexes, and a role in conducting messages between the nerves attached to it and the brain, a part of the brain.
The preliminary results of their study, published in the journal Science Translational Medicine, are based on work conducted on mice and rats with spinal cord injuries in which scientists discovered a mechanism for repairing nerve fibres after injury. They found that rodents who had had more living space, an exercise wheel, toys and the company of other rodents were more likely to recover well after a spinal injury. The reason is that damaged nerves regenerate faster because nerve cells are more likely to “reactivate” themselves.
Beneficial environmental stimuli for neurons
“Evidence suggests that people with active lifestyles may recover more after spinal cord injury than those with less active lifestyles. Our study corroborates these results. From what we have seen, it is almost as if nerve cells are better’prepared’ for regeneration and growth, which contributes to this improved recovery,” explains Professor Simone Di Giovanni, whose team led the research. When the spinal cord is damaged, nerve fibres can be damaged or, in some cases, completely cut and can no longer transmit signals correctly between the brain and the body.
To date, spinal cord injuries are difficult to treat because, while damaged bones and muscles can heal, the regeneration of damaged nerve fibres, i.e. the reconnection of the brain and body, remains a major challenge. Researchers have discovered that stimulating nerve cells by enriching the environment before an injury can help promote nerve fibre regeneration, resulting in greater “regrowth” at the injury site. In rodents, this enrichment, which took the form of a larger cage, more toys, tunnels, swings and drive wheels than usual, increased neural activity.
A drug for better “repelling” nerve fibres
“This leads to changes in gene expression, which makes the nerve more likely to regenerate. By increasing the activity of neurons that detect enriched environmental stimuli, we were able to promote the regenerative potential of nerves after spinal cord injury,” he adds. Experience has shown that all environmental stimuli, whether physical or social, increase the regeneration potential of nerve cells compared to control mice that have not benefited from them. Most importantly, the enrichment of an active lifestyle has resulted in increased growth and germination of nerve fibre at the wound site.
The next step in the experiment was to produce the same effects on humans despite an additional difficulty, namely that physically active people before a spinal injury are at risk of not fully recovering despite everything. This led the researchers to further study the underlying cellular mechanisms in order to identify a therapeutic target that could be exploited after such an injury. They were then able to mimic the effects of an active lifestyle by developing a drug that targets the same underlying pathways in cells using a key molecule called CREB-Binding Protein (CBP).
This molecule would thus have the ability to “reprogram” nerve cells in order to strengthen their ability to regenerate themselves as well as possible. Tests in mice and rats showed that administration of the drug six hours after the vein spine injury showed that the drug was effective.