“Not only does the system need to figure out where the damage was, it then needs to store that information for months,” said Michael Levin, a biologist at Tufts University. “Then, when the new growth comes out, it needs to communicate information to be read by the bone cells.”

Researchers don’t know where this information is stored. But Dr. Levin is trying to understand the phenomenon by studying planarian flatworms. They are known for their extraordinary regenerative abilities; chop one into several pieces, and each will grow a head and tail.

Eventually, scientists hope to apply what they learn to humans. “If we have the ability to tell cells what to build and when to stop,” Dr. Levin said, “most problems in biomedicine would go away.”

(http://www.autoadmit.com/thread.php?thread_id=5917330&forum_id=2#50222058)

In McConnell's experiments, he classically conditioned planarians to contract their bodies upon exposure to light by pairing it with an electric shock.[5][6] The planarians retained this acquired information after being sliced and regenerated, even after multiple slicings to produce a planarian where none of the original trained planarian was present.[6] The same held true after the planarians were ground up and fed to untrained cannibalistic planarians, usually Dugesia dorotocephala.[6][7] As the nervous system was fragmented but the nucleic acids were not, this seemed to indicate the existence of memory RNA.

(http://www.autoadmit.com/thread.php?thread_id=5917330&forum_id=2#50222252)