New discoveries that allow paralyzed people to regain their ability to walk

Spinal cord injury can lead to permanent paralysis

The neurons that "direct" walking are located in our lumbar spinal cord
.
When we walk, the brain sends instructions through pathways emanating from the brainstem to activate these neurons
.
When the spinal cord is severely damaged, this tissue's delicate communication system is disrupted, and the pathways from the brain and brainstem to the lumbar spinal cord are disrupted
.

As a result, neurons located in the lumbar spinal cord are not directly damaged, paralysis
.
Historically, paralysis caused by spinal cord injury has been permanent and irreversible
.
But incredibly, now, that may be starting to change
.

In a study recently published in the journal Nature, an international team of researchers reported that patients paralyzed by spinal cord injury were able to recover some motor function
after receiving targeted epidural electrical stimulation (EES) in areas that control leg movement.
They demonstrated the effectiveness of this therapy in 9 patients, and also demonstrated that the patients' motor function also improved after the end of the neurorehabilitation process and the shutdown of electrical stimulation.

Epidural electrical stimulation can "remodel" the spinal cord

EES is a pain relief method developed more than 50 years ago that involves implanting a flexible tablet containing multiple electrodes under the muscles and bones, above the spinal dura, the outermost membrane that surrounds the nervous system.

The electrical current transmitted by the electrodes activates neurons near the spinal cord, as well as neuronal pathways
in and out of the spinal cord.

This method has been shown to stimulate surviving neurons and improve motor function
in the case of spinal cord injury.
However, when using this method as a means of treating paralysis, there are still some challenges, such as the flexibility and stimulation pattern of the implant itself, which need to be further improved
.

In the new study, the researchers conducted a clinical trial in which they received EES in 9 severely paralyzed patients, including 3 completely paralyzed patients treated with newly designed electrodes
.
The results showed that all patients immediately recovered part of their walking ability during stimulation; Four of them were able to walk
even after the EES implant failed and no longer emitted electrical impulses.

The new study allowed nine paralyzed people to regain some ability
to walk.
(Photo: neurorestore.
swiss)

After 5 months of rehabilitation, the patient's weight-bearing capacity improved significantly and their ability to walk continued to improve
.
The researchers speculate that EES "remodeled" their spinal cords, but they don't know how EES treatment leads to neural circuit reorganization
.

The researchers tried to find evidence
in the activity of neurons while walking.
They obtained images of spinal nerve cell activity in these patients while walking before and after treatment and unexpectedly found a decrease in overall neural activity in the lumbar region of the spine in these patients after receiving EES treatment.

This means that only a small subset of specific neurons may be activated in stimuli that help improve a patient's walking function.

Discovery of key neurons in mouse models

For neuroscientists, understanding the specific role each neuron plays when walking is crucial
.
To better understand what happened, the researchers repeated the study
using laboratory mice.
In some mice with spinal cord damage, they recreated many of the key characteristics of humans when treated with EES.

The team used a machine learning method that analyzed gene expression data to identify cell types
that responded to biological stimuli.
With this approach, they pinpointed which neurons were the most important in the mouse spinal cord at different stages throughout the treatment process, and which genes were activated
.

Neurons
that respond visibly to electrical stimulation.
(Photo: neurorestore.
swiss)

They found a neuron
that showed a distinct response to both acute and chronic electrical stimulation.
These neurons are a subpopulation of V2a neurons in the brainstem and spinal cord of vertebrates, which are closely related
to aspects such as motor and limb activity.

After a series of experiments in mice, the researchers found that these specific neurons had a surprising property: after spinal cord injury, simply activating these neurons without EES treatment could help improve the patient's walking function
.
These neurons are not necessary for walking in healthy mice; But it is essential for mice with spinal cord injuries to restore motor function.

An important step towards full resumption of walking

Such experimental results suggest that certain types of spinal cord neurons lose their ability to "communicate" with the brain after spinal cord damage, but if given the right stimulus to "reawaken" them, it is expected to help patients restore motor function
.

The study gave scientists a new understanding
of the process of reorganizing spinal cord neurons.
By discovering these neurons, which are essential for restoring the ability of paralyzed patients to walk, the new study offers hope for providing targeted treatment to more paralyzed patients and restoring their ability to walk.

It shows that we can now regenerate the spinal cord by manipulating these neurons.

Although there is still a long way to go before fully restoring mobility in paralyzed people, and many challenges remain, some of the new technologies involved in this study will serve as effective tools
to guide future research on motor recovery.
This biological understanding will be an important step
towards the full recovery of motor function.

#Creative Team:

Written by: Sugar Beast

Typesetting: Wenwen

#Reference source:

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544px;text-align: left;box-sizing: border-box !important;overflow-wrap: break-word !important;">https://futurism.
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