Optogenetics is revolutionizing the field of behavioral neuroscience by enabling researchers to control the activity of individual neurons and measure the effects of those manipulations. Introduced in 2006, it was selected as Nature Methods' "Method of the Year" only four years later. Today, hundreds of labs are using the technique to explore the neurobiology of phenomena such as decision-making and neurodegenerative diseases, often with remarkable results. For example, researchers have demonstrated how light can steady the gait of a stumbling rat with Parkinson's disease.
Fluorescent imaging is a widely used technique to gain insight into biological functions. But problems can arise when external illumination is required, as in optogenetics: The same light that stimulates what's under optogenetic control can interfere with the fluorescent sensor. For instance, the same blue light that excites the FRET-based indicator for calcium activates a commonly used photo-sensitive receptor used in optogenetics.