Researchers at the Georgia Institute of Technology have announced that, using inexpensive components from a liquid crystal display (LCD) projector, they’re able to control the brain circuits in tiny laboratory animals, including freely moving worms.This is a first in the field of optogenetics, a mix of optical and genetic techniques that has allowed researchers to probe and control genetically targeted neural circuits in laboratory animals.
The illumination system is described in a recent edition of the journal Nature Methods. The prototype 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.
“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,” explained Lu.
The researchers connected the illumination system to a microscope and combined it with video tracking, enabling them to track and record the behavior of freely moving animals, while maintaining the lighting in the intended anatomical position. When the animal moves, changes to the light’s location, intensity and color can be updated in less than 40 milliseconds, according to a news release.
For their first experiment, the researchers illuminated the head of a worm (Caenorhabditis elegans) at regular intervals while the animal moved forward. This produced a coiling effect in the head and caused the worm to crawl in a triangular pattern ...
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