London, Nov 10 (IANS) Scientists have for the first time used a neural prosthetic to restore walking movement directly to the legs of non-human primates.

In the study, the researchers from Brown University in Rhode Island, US, used a wireless "brain-spinal interface" to bypass spinal cord injuries in a pair of rhesus macaques, restoring intentional walking movement to a temporarily paralysed leg. 

Walking is made possible by a complex interplay among neurons in the brain and spinal cord. 

Electrical signals originating in the brain's motor cortex travel down to the lumbar region in the lower spinal cord, where they activate motor neurons that coordinate the movement of muscles responsible for extending and flexing the leg.

To calibrate the decoding of brain signals, the researchers implanted the brain sensor and wireless transmitter in healthy macaques. The signals relayed by the sensor could then be mapped onto the animals' leg movements. 

They showed that the decoder was able to accurately predict the brain states associated with extension and flexion of leg muscles.

"The system we have developed uses signals recorded from the motor cortex of the brain to trigger coordinated electrical stimulation of nerves in the spine that are responsible for locomotion," said David Borton, Assistant Professor at Brown University.

The study, published in the Journal Nature, suggests that a brain-controlled spinal stimulation system may enhance rehabilitation after a spinal cord injury.