LCD projector used to control tiny organisms
Genetically engineered remote controlled animals ... what the? Using inexpensive and widely available technology combined with the latest techniques in optogenetics, researchers at Georgia Tech have created exactly that. Optogenetics is a mix of optical and genetic techniques that has allowed scientists to gain control over brain circuits in laboratory animals. Mary Shelly would be proud – or totally freaked out. But don't expect remote controlled poodles or parrots in your nearest pet store by Christmas, this might be a few years off.
The researchers are using components from ordinary liquid crystal display (LCD) projectors to control the brain and muscles of tiny organisms, namely worms. Using optogenetics the scientists have genetically manipulated the animals allowing them to stimulate and silence specific neurons and muscles using inexpensive LCD projectors. Red, green and blue lights from the projector activate light-sensitive microbial proteins that are genetically engineered into the worms, allowing the researchers to switch neurons on and off like light bulbs and turn muscles on and off like engines.
The illumination system includes a modified off-the-shelf LCD projector, which is used to cast a multi-color pattern of light onto an animal. The independent red, green and blue channels allow researchers to activate excitable cells sensitive to specific colors, while simultaneously silencing others.
A sequence of images showing what happens when Georgia Tech researchers illuminate the head of a worm expressing light-sensitive optogenetic reagents. The light produces a coiling effect in the head and causes the worm to crawl in a triangular pattern
“This illumination instrument significantly enhances our ability to control, alter, observe and investigate how neurons, muscles and circuits ultimately produce behavior in animals,” said Hang Lu, an associate professor in the School of Chemical and Biomolecular Engineering at the Georgia Institute of Technology.
“Because the central component of the illumination system is a commercially available projector, the system’s cost and complexity are dramatically reduced, which we hope will enable wider adoption of this tool by the research community. This instrument allowed us to control defined events in defined locations at defined times in an intact biological system, allowing us to dissect animal functional circuits with greater precision and nuance. Experiments with this illumination system yield quantitative behavior data that cannot be obtained by manual touch assays, laser cell ablation, or genetic manipulation of neurotransmitters.”
The researchers plan to use the technique to study a variety of neurons and muscles in other animals, including zebrafish and fruit fly. Lu and graduate students Jeffrey Stirman and Matthew Crane developed the tool with support from the National Institutes of Health and the Alfred P. Sloan Foundation. A paper published in the journal Nature Methods describes the research.