Reversible reaction shuts roundworms down© Neil Branda, Simon Fraser UniversityA nematode that has ingested a particular compound turns blue and stops in its tracks when exposed to ultraviolet light. The reaction is reversed with visible light and could provide a new tool for probing cell circuitry.
Scientists have stopped a tiny worm like a deer in the headlights, paralyzing it with a stream of light. The mechanism that induces the incapacitation isn't yet clear, but the paralysis occurs after the nematodes,
C. elegans, are fed a molecule known to react to light. While toxic to some of the worms, the reaction appears to be reversible in others, researchers report online October 7 in the
Journal of the American Chemical Society.
The work may add to the growing toolbox of molecules that biologists employ to study cells. By using light to trigger changes in molecules, scientists can spy on a cell's activity, witnessing what happens when messenger molecules speak with their target cells. "Light-driven reactions can be a powerful tool for studying biological processes," comments neuroscientist Ehud Isacoff of the University of California, Berkeley. Such approaches are already shedding light on the biochemistry underlying addiction, Parkinson's and other diseases in which brain circuitry goes awry.
Typical approaches "cage" a compound of interest, such as calcium, or tether it to a molecule that changes shape when energized by light. The shape change allows the compound to break out of the cage and do work, or to reach a target cell such as a nearby nerve. Though nothing was caged in this work, the molecule might be harnessed in such a way in the future.