A study set up from the collaboration between the École polytechnique fédérale de Lausanne and the University of California, Los Angeles campus, has led to a result that could represent a significant step forward in the treatment of spinal injuries, which are currently incurable. When, in fact, the spinal cord is damaged (due to a trauma, a road accident or other reasons), the transmission of nervous impulses that “govern” the muscles from the brain is interrupted, with consequent paralysis, and the damaged nerve fibers waste away. Up to now, no one has managed to regenerate these neurons and then restart this communication, which is fundamental for movement to occur.
Now, however, the Swiss and US researchers have managed to achieve a very important goal, which is an excellent starting point: the regeneration of the axons, namely the parts of the nerve cells that send out signals, creating what they themselves have defined as a new axon forest.
The secret of this regeneration (which can be compared to what happens when the branches of a tree are cut down and new buds sprout) lies in the “recipe” of substances administered, namely a cocktail of growth factors, proteins and hormones, all aimed at recreating three fundamental steps: the reactivation of the genes responsible for the formation of the axons; the recreation of an environment favourable to the development of the new filaments, and; the activation of a kind of preferred path in which the new axons find the right direction. All these three conditions have to be met, at the same time, in order for the communication between the damaged spinal cord and the brain to start up again.
For now, laboratory animals that have undergone this treatment have shown to develop, as we have said, intricate networks of axons (the “forest”). However, this has not led to true and proper movement, probably because the nerve impulses, despite having been able to pass through the lesion, have not been able to restore the correct connections. The reasons for this – say the researchers in the journal “Nature” – will be the subject of new studies, as well as possible solutions. Attempts are therefore being made to add a certain ingredient to the recipe, in order to try to create the contact that will make the electrical impulses required for movement pass through the “right” way.