Researchers examine cell regeneration
SLIPPERY ROCK, Pa. - Who would have thought that a small worm, less than an inch in length found in streams on the Slippery Rock University campus and around the world, might someday provide answers to re-generation of human body parts?
Simon Beeching, SRU professor and a number of undergraduate students did and they are now searching for the answers using brown planaria, a simple flatworm organism.
Talking from his Vincent Science Center lab, Beeching explains the campus research starts with research already confirmed by the black planaria, close cousin of the brown planaria in the animal kingdom.
"The brown planaria, which is less than an inch long, but can be spotted in the streams on campus and all over North America. We are looking at how the brown planaria know how to avoid an area of their habitat where another of their species has been injured and how they can regenerate their bodies," he said.
"We have been able to replicate experiments done with the black planaria using the brown species to show that the worms can tell when one of their own has been hurt. We don't know if it is chemical cues, if they can 'smell' it, or if there is some other factor. This 'avoidance' behavior has been clearly demonstrated in one species of flatworms, and we have now extended the research to a second species," he said.
Beeching and his student biology researchers have collected the brown planaria from campus streams for their work. He said there are distinctive physical differences in the two species, "but, either way, they are very simple animals."
"There is a general term for these kinds of chemical cues called an "alarm substance," he said. "We are not sure exactly what it is, but it is known in a number of fish and snail species as well. For example we have seen that in a school of fish, when one fish is attacked by predator, the other fish do not need to see or hear the attack, but can detect it, possibility through chemicals excreted by the tissues of the attacked fish."
"In general, it appears that some chemical compound, the alarm substance, within the tissues is released on injury and detection of those chemical produces escape or avoidance in those detecting it. Researchers demonstrated this alarm substance in a simple flatworm, the black planaria, for the first time in 2000, and went on to demonstrate impressive learning in these simple animals using these chemical cues," he said.
Beeching, and a series of SRU undergraduates have been working on the topic and related issues for a decade.
"In our research, we found the brown planeria may be exhibiting similar behavior," he said. "Our experiment involved a basic procedure of taking one of the worms and grinding it up in water. We then put another worm in an aquatic medium and using a micropipette carefully add a small quality of the fluid. We then look to see any change in behavior. We found the second flatworm avoided the area after the medium was administered," Beeching said.
"Of course, we had to run a control, just to be sure of what we were seeing. We replicated the experiment, but this time adding only a small quantity of pure water, rather than the medium, and found the worm, in this case, did not avoid the area," he said.
"We call this an 'avoidance response," he said. We knew it had been shown in the black planeria, and we were able to show it in the brown planeria species too," he said. "We believe it has something to do with the worm's tissues, or the chemicals released when the tissues are broken."