Optogenetic techniques have recently been applied to peripheral nerves as a scientific tool with the translatable goal of alleviating a variety of disorders, including chronic pain, muscle fatigue, glucose-related pathologies, and others. When compared to the electrical stimulation of peripheral nerves, there are numerous advantages: the ability to target molecularly defined subtypes, access to opsins engendering neural inhibition, and optical recruitment of motor axons in a fashion that mimics natural recruitment, which eliminates the fatigue roadblock inherent to functional electrical stimulation. The ability to control peripheral nerves situated under deep tissue structures with transdermal, optical signals would be of enormous benefit, integrating all of the advantages conferred by optogenetics while averting the drawbacks associated with implantable devices, such as mechanical failure, device tissue heating, and a chronic foreign body response.
We work to develop novel molecular and optical methods in an effort to enable this transdermal optogenetic peripheral nerve control. A further example of a potential clinical application involves optogenetically targeting the vagus nerve, a peripheral cranial nerve implicated in numerous ailments, including epilepsy, migraines, obesity, hypertension, fibromyalgia, Crohn’s disease, asthma, depression, and obsessive-compulsive disorder. An efficient method of stimulating the vagus nerve with minimal side-effects and high target specificity, such as described here, may have profound implications to the study of various illnesses and disabilities.