Shining a light on optogenetics: Advances in electronics and protein engineering advance the field of optogenetics to study the activity of neuronal networks.

Abstract

Optogenetics is relatively new and has attracted much interest since the first publications from the field in the early 2000s. Both researchers and the media are fascinated by the notions it conjures of bionic implants. Notwithstanding potential applications, the technology has quickly become an important research tool in neuroscience with potential for developing a range of novel therapeutic approaches. Scientifically, optogenetics combines advances in optics, small‐scale power generation, electronics, the manipulation of cellular activity and gene therapy, to enable the study of complete systems, including neural networks in animals and humans. Moreover, some recent studies have highlighted potential applications in plants as an alternative to genetic modification (GM) for targeted alteration of phenotypes. Since the first experiments [1], optogenetics has consistently expanded in scope and definition. It can now be defined as the use of light to stimulate cells into which exogenous genes coding for light‐sensitive proteins have been introduced, and to measure the response of these transformed cells to stimulation. Typically, the light is generated by an artificial source powered by a battery or external electric field. The definition also embraces treatments for some forms of blindness based on implanting light‐sensitive proteins in the retina. However, much of the fields' focus revolves around the optical components, their implantation in the body, and the interface with the target cells to stimulate gene expression with high spatial and temporal resolution. In practice, an implanted LED or other light source illuminates a specific target area. Within this area, the target cells—genetically modified to express specific light‐sensitive proteins—react to this light by changing their membrane potential, which in turn starts signal cascades that activate or shut down specific target genes. The key biological challenges of optogenetics are the development of appropriate light‐sensitive proteins, mechanisms for delivering their genes to specific cells, …