On the development of optical peripheral nerve interfaces

Abstract

Limb loss and spinal cord injury are two debilitating conditions that continue to grow in prevalence. Prosthetic limbs and limb reanimation present two ways of providing affected individuals with means to interact in the world. These techniques are both dependent on a robust interface with the peripheral nerve. Current methods for interfacing with the peripheral nerve tend to suffer from low specificity, high latency and insufficient robustness for a chronic implant. An optical peripheral nerve interface may solve some of these problems by decreasing invasiveness and providing single axon specificity. In order to implement such an interface three elements are required: (1) a transducer capable of translating light into a neural stimulus or translating neural activity into changes in fluorescence, (2) a means for delivering said transducer and (3) a microscope for providing the stimulus light and detecting the fluorescence change. There are continued improvements in both genetically encoded calcium and voltage indicators as well as new optogenetic actuators for stimulation. Similarly, improvements in specificity of viral vectors continue to improve expression in the axons of the peripheral nerve. Our work has recently shown that it is possible to virally transduce axons of the peripheral nerve for recording from small fibers. The improvements of these components make an optical peripheral nerve interface a rapidly approaching alternative to current methods.

Optogenetic Neuromodulation of the Urinary Bladder

“…Additional restriction of expression sites can be achieved through routes of administration. Transduction efficiency can be maintained through intranerve, intrathecal, or direct dorsal root ganglia injection, while intravascular and intraperitoneal injection, which requires higher viral density, provide a less invasive and easy way (27). Lastly, designs of promoters can also induce cell-type restriction in AAVs.…”

Receptor variants and the development of centrally acting medications

“…In combination with other technologies, such as optogenetics. 55 - 57 These approaches will be of great value to neuroscience drug discovery. Application of these approaches will allow in-depth knowledge of the actions of different compounds on neuronal function, of relevance both for how a compound may control the disease, and also to aid understanding of side effects.…”

Biomedical and Tissue Engineering Strategies to Control Foreign Body Reaction to Invasive Neural Electrodes

“…Unfortunately, the standard control systems of prosthetic limbs rely on surface electromyogram, which is mainly limited by problems of high latency, as well as low specificity and robustness in long-term implants ( Anderson and Weir, 2019 ). Although some of the current peripheral nerve interfaces can shorten latency and provide single axon specificity, their performances tend to degrade with time due to the biological response of the organism to the electrode, which is triggered by the damage provoked by the implant procedure itself ( Anderson and Weir, 2019 ). The body tends to insulate and exclude the foreign material from the surrounding microenvironment, leading to scar tissue growth around the device that is made of a fibrous capsule.…”