Blogs / 80beats

Scientists recently used treadmill exercise, drugs, and electrical stimulation to train paralyzed rats to walk once again, demonstrating a way to possibly treat spinal injuries in humans, which at present are basically untreatable.

In a spinal injury, the neural circuits connecting the brain to the muscles that control walking become damaged or severed, leaving an individual paralyzed. In able-bodied people, these “walking circuits” spring into action when they receive a signal from the brain, but if the spinal cord is damaged, the message from the brain never arrives. When contact with the brain is lost, the circuits shut down [The Guardian]. In the study, published in Nature Neuroscience, researchers manipulated these circuits and produced movement that was “almost indistinguishable” from normal walking. See for yourself in the embedded video.

(more…)

A chemical compound similar to the blue food dye found in blue M&Ms and blue Gatorade could one day be used to treat people with spinal injuries, and could reduce damage and improve mobility, according to a new study. Researchers found that when they injected the compound Brilliant Blue G (BBG) into rats suffering spinal cord injuries, the rodents were able to walk again, albeit with a limp. The only side effect was that the treated mice temporarily turned blue [CNN].

The same research team had previously shown that ATP, a vital energy source that keeps the body’s cells alive, quickly pours into the area surrounding a spinal cord injury after it occurs. Unfortunately, the release of ATP at hundreds of times the normal level kills off healthy, uninjured motor neuron cells by flooding them with a deluge of molecular signals, making the initial injury worse [BBC News]. In the new experiment, described in the Proceedings of the National Academy of Sciences, the blue compound prevented ATP from latching on to the motor neuron cells, and therefore prevented the secondary damage that occurs in the hours after a spine injury.

(more…)

In a new study, researchers attached electrodes to individual neurons in monkeys’ brains and then rerouted those neuronal signals through a brain-machine interface, which converted them into electrical signals that controlled the monkeys’ own paralyzed muscles. Researchers say this roundabout feat of bioengineering could eventually lead to new treatments and prosthetics for paralyzed people.

The implant exploits the fact that even when the neural connection between a brain region and the muscles it controls is severed or damaged by, say, a stroke or spinal injury, the controlling neurons remain active. For example, people living with quadriplegia who try to move their arm still generate arm-movement signals in the motor cortex of their brain, even after several years of paralysis [New Scientist]. The new study is the first to send the signals back to the user’s own muscles, as opposed to related research in which the signals are fed into electronic devices.

(more…)

A man who was paralyzed below the waist 20 years ago is walking again, thanks to a robotic “exoskeleton” that moves his legs and can even navigate up and down hills. The inventors of the device, dubbed the ReWalk, say the experimental technology can give paraplegics a psychological boost through renewed mobility, and can also help people avoid medical problems caused by long-term wheelchair use.

One of the first paraplegics to test out the device is Radi Kaiof, a former Israeli paratrooper who has been paralysed for the last 20 years following an injury during his service in the Israeli military. He says the device has changed his life. “I never dreamed I would walk again. After I was wounded, I forgot what it’s like. Only when standing up can I feel how tall I really am and speak to people eye to eye, not from below” [BBC News].

(more…)