Visual system surprise

The soil-dwelling model organism C. elegans, long assumed to lack any visual system whatsoever, in fact appears to be strongly responsive to light, according to a linkurl:paper;http://www.nature.com/neuro/journal/vaop/ncurrent/abs/nn.2155.html published online yesterday (July 6) in Nature Neuroscience. The study identifies four sensory neurons that act as photoreceptor cells driving this phototaxic behavior, and suggests a conservation of phototransduction between vertebrates and worms. "The research is very compelling," said linkurl:Aravinthan Samuel,;http://www.physics.harvard.edu/people/facpages/samuel.html who studies sensory inputs and navigational behaviors in C. elegans at Harvard. "It's the strongest evidence so far that phototaxis is a bona fide modality in worms." linkurl:C. elegans;http://www.the-scientist.com/article/display/54694/ live in the darkness of soil and lack eyes, so the tiny roundworms were never chosen as a candidate to study sensory response to light stimulus. But linkurl:Shawn Xu,;http://www.lsi.umich.edu/facultyresearch/labs/xz-xu a biologist at the University of Michigan, reasoned differently. "There must be some reason they want to stay in soil,"...