Reconnecting Brain to Muscle

Spinal cord injury causes a disconnection between brain and muscle. Recent research in neuroprostheses has shown that neurologically intact animals and tetraplegic humans can use intracortically recorded motor cortex (M1) activity, decoded by computers, to control external devices, such as computer cursors and robotic arms. Now, researchers have demonstrated that monkeys with temporarily paralyzed wrists and artificial connections between single M1 neurons and wrist muscles can learn to use this brain activity to control stimulator-evoked wrist action.

The authors trained two monkeys to make isometric wrist flexion and extension actions to control movement of a cursor on a computer screen. Each animal then learned to activate single M1 neuro…