There is still no solution for people with paralysis. Steps are being taken slowly in the right direction. For example, researchers have now been able to regrow some neurons in mice, leading to recovery of spinal nerves.
Scientists from the University of California and Harvard, among others, have done so – not the least Discover a critical element Which led to the restoration of spinal functions in paralyzed mice. The crux of the matter is to allow specific neurons to grow back in their natural location: random regeneration has been shown to be ineffective.
Time to refine
The same research team had already been in place five years earlier I invented a method To activate the axes. Thus, these small nerve fibers that connect neurons and allow them to communicate with each other were able to grow back after spinal cord injury in the rodents. Although it has been possible to successfully regenerate axons in severe spinal cord injuries, functional recovery has remained a major challenge.
So scientists made a new, more complex attempt. First, they chose to regenerate axons from specific subsets of neurons, and second, they ensured they had access to their natural habitat. It worked: it led to functional recovery of the mice’s spine. To achieve this exceptional result, a modern form of genetic analysis was used to identify the groups of nerve cells that allow improvement of partial spinal cord injury.
Crucial visions for the future
But simply regenerating the axons of neurons close to the spinal cord injury, without specific guidance, had no effect on functional recovery. However, when the approach was refined using chemical signals to direct axons toward their normal destination in the lumbar spine, significant improvements occurred in a mouse model with complete spinal cord injury. The steps can literally be taken again.
“Our study provides important insights into the complexity of axon regeneration and the requirements for functional recovery after spinal cord injury,” said Michael Sophronio, a professor of neuroscience at UCLA. “It is essential to not only regenerate axons in the vicinity of spinal cord injury, but also effectively direct them toward their normal destination in order to achieve neurological recovery,” he explains.
Problem with people
This discovery could have serious consequences for people with long-term paralysis. The idea that specific groups of neurons need to be directed to normal target areas is a promising strategy for developing treatment approaches aimed at restoring neuronal function in large animals and humans. But the point is that this regeneration becomes much more difficult at greater distances, as is the case with humans, for example. The researchers concluded that this is an important step “to open the framework for achieving meaningful recovery in spinal cord injuries and accelerating recovery in other central nervous system injuries.”
Spinal cord injury and the role of axons
There are currently approximately 4 million people with spinal cord injuries in the world. About 130,000 cases are added each year. 82% of them are men. The life expectancy of people with a spinal cord injury is much lower: those with a spinal cord injury at the chest level at age 40 live on average 12.5 years shorter. In a spinal cord injury, communication between nerve cells in the brain and spinal cord is broken. Neurons fail to regenerate damaged axons.
An axon, also called a nerve fiber, is an extension of a nerve cell and transmits electrical impulses. Axons are responsible for transmitting information in the nervous system. They are about a micrometer in diameter, but can be up to a meter in length. It is surrounded by myelin, a type of insulating layer through which electrical signals are conducted more quickly.
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