Recently, a successful study involving lab rats at the Swiss Federal Institute of Technology may provide hope for those who have a spinal cord injury. In this experiment, as published in Science Translational Medicine, paralyzed rats are subjected to electrical stimulation of the spinal cord in an effort to mimic signals from the brain. The rats that underwent treatment were able to walk again, suggesting that this sort of therapy may be the future of effective treatment for spinal cord injuries in humans.

While this kind of technology has been around for several years, the recent breakthrough at SFIT allows paralyzed rats to walk longer, further and with greater control than previously possible. In this particular technique, researches surgically implant two electrodes into the spine, one above the site of injury and one below. By communicating directly with each other, the two electrodes are then able to effectively bypass the injured area. With the new technique, rats with completely severed spinal cords are given some basic training and then attached to a harness that lifts them onto their hind legs. The machine then transmits electrical signals varying in length, pulse and frequency to allow the rats to begin to walk and step up small steps. The system’s frequency varied between 20 and 90 hertz, or cycles per second, in contrast to the traditional constant 40 hertz. Because this method mimics the natural firing of neurons, the rats’ nerves were able to respond to the signals for a much longer period of time. After comparing the number of steps taken by the rats using the traditional method versus the new method, researchers found that rats were able to walk 1,000 steps without collapsing under the new method, almost twice the amount taken before the trial.

“There has been so much focus in the past on trying to regenerate or repair damaged nerves using stem cells, and these researchers have bypassed the nerve altogether using artificial electrodes,” said Honors Physiology, Environmental Biology and Honors Biology teacher Megan Swanson. “While electrodes can be used to stimulate the nerves, the way currents are naturally transmitted from cell to cell using ion channels is quite unique.”

Damage to the spinal cord can occur due to anything from illness to accident, and in some cases, the hope of forever being able to walk again is highly improbable. The spinal cord acts as a line of communication between the brain and the rest of the body. The brain sends electrical signals through the spinal cord into the nerves that control muscles in one’s arms, legs and torso. Without the spinal cord to facilitate this transmission, a person cannot voluntarily move their own limbs and often cannot feel physical stimulation in any area from the waist down. Likewise, sensory nerve signals from muscles are interrupted on their way to the brain. In the case of the new treatment performed at SFIT, a machine is able to read the signals sent out by the brain and relay these signals to the body.

While epidural electrical stimulation has shown to be effective in humans, the study conducted at SFIT will allow for greater control of movement for extended periods of time. Human trials using this method are expected to begin as early as this summer. Scientists hope that with such promising results, paralysis victims may have a better quality of life in the future.