Remote-controlled rats have been created by scientists who took over the walking ability of paralysed animals using electrical implants.
The research could lead to rehabilitative therapies that may help partially paralysed human patients with spinal injuries walk more naturally, it is claimed.
Rats used in the study were paralysed by having their spinal cords severed in the middle back.
No signals from their brains were able to reach the lower spinal cord. But sending an electric current into spinal nerves via surgical implants enabled them to walk while held upright on a treadmill.
Movements could be controlled by altering the electrical signal. Treated animals walked over one thousand successive steps without failure, and negotiated stairs of various heights and lengths.
Lead researcher, Dr. Gregoire Courtine, from Ecole Polytechnique Federale de Lausanne (EPFL) in Switzerland, said: “We have complete control of the rat’s hind legs. The rat has no voluntary control of its limbs, but the severed spinal cord can be reactivated and stimulated to perform natural walking. We can control in real-time how the rat moves forward and how high it lifts its legs.”
The research is part of a European project called NEUWalk that aims to test the epidural electrical stimulation (EES) technology in human patients as early as next summer.
Scientists have designed the Gait Platform – a human-sized version of the apparatus used to study walking in the rats – for the clinical trials.
It consists of a treadmill and overground support system with infrared cameras to detect reflective markers on the patient’s body.