The functional regeneration of the spinal cord is possible thanks to the growth of new fibers, and not – as previously suspected – the regeneration of nerve connections damaged during trauma, scientists from the USA have found.
It is known that people with milder spinal cord injuries often experience significant core regeneration. For years, scientists have been studying the mechanism of this regeneration.
Mark Tuszynski, together with colleagues from the University of California, conducted research on monkeys whose right part of the so-called cortico-spinal tract – a bundle of nerve fibers responsible in primates for deliberate movements of the right side of the body. Four to eight weeks after surgery, the animals regained right arm and leg mobility.
In the animal autopsy material, researchers noticed a strong growth of new nerve fibers originating from the undamaged left side of the cortico-spinal tract.
New fibers cut through the middle of the spinal cord and made new connections with the motor neurons on the right side of the spinal cord. This made it possible to transmit nerve impulses to the muscle fibers that could not be activated due to the cutting of the nerves during the procedure.
In their work, the scientists emphasize that there is a significant difference in the mechanism of core regeneration after injury in primates and rodents. So far, this type of experiment has been carried out mainly in mice and rats, in which the growth of new nerve fibers was not as strong as in monkeys.
According to the researchers, further studies in primates are required to understand the mechanisms that enable the growth and formation of new nerve fiber connections after spinal cord injuries in humans. Only they will allow us to understand how to help patients after injuries. (PAP)