Restoring motor function using optogenetics and neural engraftment

Schematic representation of a combinatorial closed-loop system to restore functionality to paralysed muscles, enabling control of specific motor functions. Briefly, intraneural grafts of optogenetically-engineered stem cell-derived motor neurons are placed closed to the motor-entry point of the target muscle, leading to its reinnervation (1) or, where intact, viral vectors are used to express opsins in endogenous motor axons. Next, a brain-machine interface embedded in the primary motor cortex (2), relays intended motor commands via an external neural decoding and processing unit (3), which then wirelessly transmits execution signals to an implanted optoelectronic stimulator (4) that activates the engrafted motor neurons (5) to induce muscle contraction (6). The implanted optoelectronic device can then relay feedback information from the muscle or nerve to the processing unit (not shown).