Death comes to all animals, but how? A fascinating new study involving microscopic worms suggests that the transition from living to dead may be less like the flipping of a switch and more like the propagation of a wave through the body.
For the worms in the study -- transparent roundworms of the species C. elegans that measure about 1 millimeter in length -- the wave of death is a beautiful fluorescent blue.
The death wave (a.k.a. "death fluorescence, or DF) starts in the worms' intestines and spreads via "a stereotyped process of self-destruction involving an intra- and intercellular cascade of cellular necrosis," the researchers wrote in a paper describing their findings.
In other words, the wave spreads predictably from cell to cell until the entire organism has bought the farm.
"It's like a blue grim reaper, tracking death as it spreads throughout the organism until all life is extinguished," study co-author Prof. David Gems, professor of biogerontology at University College London's Healthy Ageing Institute, said in a written statement issued by the university.
The study's first author, Dr. Cassandra Coburn, offered another metaphor for the way in which death spreads across the worms' bodies.
"I like to think of it as a building that burns down the same way every time," Coburn, who at the time of the research was a student in Gems' laboratory, told The Huffington Post in an email. "It wasn't designed to spread fire like that but due to certain features like stairs, etc., it always will."
What exactly causes the blue hue? A molecule known as anthranilic acid, according to the statement.
Coburn cautioned that the finding applies only to worms but called it a step toward gaining a better scientific understanding of the death process in humans. That might lead eventually to strategies to slow the aging process and forestall death.
As Gems put it to New Scientist, "In a stroke or heart attack, cells are killed by blood supply being blocked off. They are left surrounded by living cells, and this damaged area can start to kill off the cells around it. If we can understand how this death propagation works in C. elegans, we might be able to one day reduce [similar] damage in patients."
One way that might be accomplished would be by developing drugs that interrupt the progression of this lethal wave, according to Coburn. "But," she added, "we're very, very, very far from 'curing death.'"
The study was published in the July 2013 issue of PLOS Biology.