Scientists at the David Geffen School of Medicine at UCLA and researchers from the University of Zurich in Switzerland have discovered stunning information on how nerves in the spinal cord, even in cases of paralysis, can be stimulated to elicit a walking response, without communication between the brain and the nerves. The researchers used a combination of treatments to enable rats with severed spinal nerves to bear the full weight of their bodies and run for up to 30 minutes.
The treatment consisted of drugs known as serotonergic agonists, electrical stimulation applied to nerves below the spinal cord injury, and rehabilitation on a slow moving treadmill. When the nerves were activated with electrical currents, it activated evolutionarily primitive nerve connections in the spinal cord to elicit movement in the rats’ limbs without information from the brain.
At first, the rats were only able to move their back legs for a small amount of time. Over a week, the rats could run and walk without support. After a few weeks, the rats were able to fully support their own weight and run forward, backward, and sideways for up to 30 minutes. However, the rats remained dependent on the mix of drugs and electrical stimulation to make their legs work.
Researchers from the University of Zurich also reported that they are developing a series of electrodes for insertion along the spinal cord. They expect to begin human trials in about four years.
Previously, scientists have been able to generate movement in the legs of paralyzed human subjects in the past. Until the most recent study, published in the most recent online edition of Nature Neuroscience, they had never been able to elicit continuous walking and full weight bearing in the paralyzed rats.
The Christopher and Dana Reeve Foundation and many other contributors funded the study. Scientists and support foundations hope to inspire further research leading to a cure for paralysis for patients with severe spinal cord injuries. One of the most remarkable implications of the study is that, ‘nerve fibers do not need to regrow in order for a paralyzed patient to walk again.’
Combined with neuroprosthetic devices, which may allow a communication bridge from the brain across the injured spinal cord, the data from the current study has brought scientists one step closer to finding a cure for paralysis.
(pic from cdn-write.demandstudios.com)