Worm Light Views

Toys & Games

C. elegans is a favorite subject of neurobiologists because it has a simple nervous system. Over the years, researchers have figured out how the worm detects chemicals, heat, and other clues to its environment. However, researchers generally assumed that the worm, which lacks eyes, was insensitive to light, says Shawn Xu, a neurobiologist at the University of Michigan, Ann Arbor. But Xu and his colleagues noticed that the millimeter-long worms sometimes seemed to wriggle away from the bright light of their microscope.

Investigating further, Xu's graduate student Alexander Ward and postdoc Jie Liu found that flashes of light aimed at a swimming worm caused it to reverse course (see video). The worms were most sensitive to long ultraviolet (UV-A) light, and additional experiments indicated that this wavelength, which damages skin in sun-worshiping people, is downright lethal to the worms, the researchers report online 6 July in Nature Neuroscience. The scientists reason that the ability to detect UV-A may help C. elegans stay safely underground.

To figure out how the sensory system works, the researchers turned lasers on the worm's neurons. C. elegans has just 302 neurons, whose functions and connections have been well studied. Destroying four pairs of sensory neurons eliminated the worm's ability to respond to light. Other experiments revealed that flashes of light spur at least one of these sensory neurons to produce weak electrical currents. These currents didn't flow without two molecular components also found in vertebrate eyes: cyclic nucleotide-gated channels, which let ions pass across a cell membrane, and a messenger molecule called cGMP.

The politician, from the album Glow (2009) by Worm Is Green Artist : Worm Is Green Album : Push Play (2005) Album version Musician: Worm is Green Title: Undercover Genre: Electro Indie Album: Automagic Autor: Asgeirsson / Hannesson / Hannesson / Hafsteinn Jonsson Language: English Country: Iceland Year: 2002 Interprete: Worm is Green Titulo: Undercover Genero... one of the finest songs by Worm Is Green from their alb Push Play (2005) He was feeling optimistic His heart was tickin' click tick tick Synthetic hopes of a different day Sparks flew across his vains The stars are shining from a light engine The dj...