Researchers have found a way to transfer memories in snails via injection

  • Researchers have found a way to transfer memories in snails via injection

Researchers have found a way to transfer memories in snails via injection

"Obviously further work needs to be carried out to determine whether these changes are robust and what are the underlying mechanisms", said Prof Seralynne Vann, who studies memory at Cardiff University.

UCLA biologists report they have transferred a memory from one marine snail to another, creating an artificial memory, by injecting RNA from one to another. "If circulating neural RNAs can transfer behavioral states and tendencies, orchestrating both the transient feeling and the more permanent memory, it suggests that human memory-just like mood-will only be explained by exploring the interplay between bodies and brains".

The research, published in the journal eNeuro, could provide new clues in the search for the physical basis of memory.

Scientists have long believed memories were stored in synapses. Experiments in the 1960s, however, suggested RNA could play a role in making memories, though the work was largely written off as irreproducible.

"I think in the not-too-distant future, we could potentially use RNA to ameliorate the effects of Alzheimer's disease or post-traumatic stress disorder", said David Glanzman, senior author of the study and a UCLA professor of integrative biology and physiology and of neurobiology.

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 was completely arbitrary which synaptic connections got erased", Glanzman says.

According to the researchers, the experiments show how essential parts of the memory trace, or engram, that gives rise to sea hare sensitisation are held in RNA, rather than in the connectivity of brain cells as traditional neuroscience dictates. He picked Aplysia because it has been a longtime model organism for memory studies.

As expected, the control group of snails did not display the lengthy contraction. Despite the similarities, a snail has only about 20,000 neurons (nerve cells) in its central nervous system compared to the human nervous system, which has about a 100 billion. Those that had not been given the shocks contracted for only about one second.

Once the snail had established an involuntary defensive reflex, the team extracted its ribonucleic acid (RNA). The snails had been "sensitised" to the shock.

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. But the ones injected with RNA from the trained snails? Moreover, a specific cellular adjustment that underlies sensitization in Aplysia, sensory neuron hyperexcitability, can be reproduced by exposing sensory neurons in vitro to RNA from trained animals.