Memory transfer has been at the heart of science fiction for decades, but it's becoming more like science fact.
A group of scientist from the University of California (UCLA) have successfully transplanted memories from one snail to another. When Glanzman repeated the experiment with RNA from sea snails that had been hooked up to wires but not shocked, the reflex behaviour did not transfer.
To test their hypothesis, they trained sea snails.
The research, published in the journal eNeuro, could provide new clues in the search for the physical basis of memory.
That is, until researchers injected ribonucleic acid (RNA) from the trained snails into the second group.
Researchers in the United States achieved the feat by first teaching a group of Aplysia snails - using a series of mild electric shocks - to associate potential danger with a harmless tap on the outside of their shells. The shocks enhance the snail's defensive withdrawal reflex, a response it displays for protection from potential harm.
Glanzman wanted to know if the RNA from shocked snails actually affected the neuronal connections of the snails receiving the injections any differently than RNA from nonshocked snails.
In his team's latest experiments, Glanzman and his colleagues zapped snails' tails, then pulled the abdominal neurons from the shocked snails, extracted their RNA, dissolved the RNA into deionized water, and injected the solution into the necks of snails that had never been shocked.
The snails that received the implants had a defensive reaction of about 40 seconds after the implants, even though they had not had a reaction previously, the BBC reported.
They saw a similar effect when they did the same thing to sensory nerve cells being studied in petri dishes.
"These are marine snails and, when they are alarmed, they release a handsome purple ink to hide themselves from predators", Glanzman said in a statement. "So these snails are alarmed and release ink, but they aren't physically damaged by the shocks", he said. Kaang notes there are "many critical questions that need to be addressed to further validate the author's argument", such as what kinds of noncoding RNAs are specifically involved, how are the RNAs transferred among neurons, and how much do RNAs at the synapse play a role?
In a statement for The Guardian, Glanzman commented on the nature of the experiment, noting that the type of memories that were transplanted from one snail to another was crucial to the success of the procedure. It is now understood to have other important functions besides protein coding, including regulation of a variety of cellular processes involved in development and disease.
Researchers say the cells and molecular processes of snails are similar to that of humans.