Optogenetic control of muscle function
We are developing optogenetic neural grafts capable of linking an optoelectronic control system to host muscle. The long-term aim is to restore motor function and treat paralysis in patients suffering from spinal cord injury or neuromuscular disease with an implantable neural prosthesis. The idea is to use grafted optogenetic motor neurons derived from stem cells, embedded in a stem cell-derived glial scaffold, as a body-machine interface between an optoelectronic pacemaker device and recipient skeletal muscle. Due to the photosensitivity of the graft, muscle contractions can then be specifically triggered by light signals transmitted to the graft via implanted micro-LEDs. In a recent proof-of-principle study, my group and collaborators have shown that such peripherally implanted optogenetic motor neuron grafts can not only survive and extend axons to successfully re-innervate denervated muscles, but can also relay rhythmic contraction patterns from an artificial control system to skeletal muscle in vivo. While such a device, once fully developed, would not offer a cure for spinal cord injury or ALS, the quality of life for affected patients could be dramatically improved by restoring vital motor functions, such as breathing.