Biologists 'transfer' a memory

May 14, 2018, University of California, Los Angeles
Memories can be transferred between organisms by extracting ribonucleic acid (RNA) from a trained animal and injecting it into an untrained animal, as demonstrated in a study of sea snails published in eNeuro. The research provides new clues in the search for the physical basis of memory. Credit: Bédécarrats et al., eNeuro (2018)

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. This research could lead to new ways to lessen the trauma of painful memories with RNA and to restore lost memories.

"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. The team's research is published May 14 in eNeuro, the online journal of the Society for Neuroscience.

RNA, or ribonucleic acid, has been widely known as a cellular messenger that makes proteins and carries out DNA's instructions to other parts of the cell. 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.

The researchers gave mild electric shocks to the tails of a species of marine snail called Aplysia. The snails received five tail shocks, one every 20 minutes, and then five more 24 hours later. The shocks enhance the snail's defensive withdrawal reflex, a response it displays for protection from potential harm. When the researchers subsequently tapped the snails, they found those that had been given the shocks displayed a defensive contraction that lasted an average of 50 seconds, a simple type of learning known as "sensitization." Those that had not been given the shocks contracted for only about one second.

The life scientists extracted RNA from the nervous systems of marine snails that received the tail shocks the day after the second series of shocks, and also from marine snails that did not receive any shocks. Then the RNA from the first (sensitized) group was injected into seven marine snails that had not received any shocks, and the RNA from the second group was injected into a control group of seven other snails that also had not received any shocks.

UCLA Professor David Glanzman holding a marine snail. Credit: Christelle Snow/UCLA

Remarkably, the scientists found that the seven that received the RNA from snails that were given the shocks behaved as if they themselves had received the tail shocks: They displayed a defensive contraction that lasted an average of about 40 seconds.

"It's as though we transferred the memory," said Glanzman, who is also a member of UCLA's Brain Research Institute.

As expected, the control group of snails did not display the lengthy contraction.

Next, the researchers added RNA to Petri dishes containing neurons extracted from different snails that did not receive shocks. Some dishes had RNA from marine snails that had been given electric tail shocks, and some dishes contained RNA from snails that had not been given shocks. Some of the dishes contained sensory neurons, and others contained motor neurons, which in the snail are responsible for the reflex.

When a marine snail is given electric tail shocks, its sensory neurons become more excitable. Interestingly, the researchers discovered, adding RNA from the snails that had been given shocks also produced increased excitability in sensory neurons in a Petri dish; it did not do so in motor neurons. Adding RNA from a marine snail that was not given the tail shocks did not produce this increased excitability in sensory neurons.

David Glanzman holding a marine snail. Credit: Christelle Snow/UCLA

In the field of neuroscience, it has long been thought that memories are stored in synapses. (Each neuron has several thousand synapses.) Glanzman holds a different view, believing that memories are stored in the nucleus of neurons.

"If memories were stored at synapses, there is no way our experiment would have worked," said Glanzman, who added that the marine snail is an excellent model for studying the brain and memory.

Scientists know more about the cell biology of this simple form of learning in this animal than any other form of learning in any other organism, Glanzman said. The cellular and molecular processes seem to be very similar between the marine snail and humans, even though the snail has about 20,000 neurons in its central nervous system and humans are thought to have about 100 billion.

In the future, Glanzman said, it is possible that RNA can be used to awaken and restore memories that have gone dormant in the early stages of Alzheimer's disease. He and his colleagues published research in the journal eLife in 2014 indicating that lost memories can be restored.

There are many kinds of RNA, and in future research, Glanzman wants to identify the types of RNA that can be used to transfer memories.

Explore further: One-month worth of memory training results in 30 minutes

More information: RNA from Trained Aplysia Can Induce an Epigenetic Engram for Long-Term Sensitization in Untrained Aplysia, eNeuro, doi.org/10.1523/ENEURO.0038-18.2018

Related Stories

One-month worth of memory training results in 30 minutes

March 8, 2018
A new study shows that when participants are taught an effective strategy for a working memory training task, they quickly improve their performance in the same way as those who have undergone typical working memory training ...

Lost memories might be able to be restored, new study indicates

December 19, 2014
New UCLA research indicates that lost memories can be restored. The findings offer some hope for patients in the early stages of Alzheimer's disease.

Brain training increases dopamine release

August 5, 2011
It is known that training can improve working memory. In a new study in Science, researchers from Karolinska Institutet, Umeå University, Åbo Akademi University, and the University of Turku show for the first time ...

Recommended for you

Aggression neurons identified

May 25, 2018
High activity in a relatively poorly studied group of brain cells can be linked to aggressive behaviour in mice, a new study from Karolinska Institutet in Sweden shows. Using optogenetic techniques, the researchers were able ...

The brain's frontal lobe could be involved in chronic pain, according to research

May 25, 2018
A University of Toronto scientist has discovered the brain's frontal lobe is involved in pain transmission to the spine. If his findings in animals bear out in people, the discovery could lead to a new class of non-addictive ...

Doctors fail to flag concussion patients for critical follow-up

May 25, 2018
As evidence builds of more long-term effects linked to concussion, a nationwide study led by scientists at UCSF and the University of Southern California has found that more than half of the patients seen at top-level trauma ...

Bursts of brain activity linked to memory reactivation

May 24, 2018
Leading theories propose that sleep presents an opportune time for important, new memories to become stabilized. And it's long been known which brain waves are produced during sleep. But in a new study, researchers set out ...

Study suggests brainwave link between disparate disorders

May 24, 2018
A brainwave abnormality could be a common link between Parkinson's disease, neuropathic pain, tinnitus and depression—a link that authors of a new study suggest could lead to treatment for all four conditions.

Researchers define molecular basis to explain link between a pregnant mother's nutrition and infant growth

May 24, 2018
For years, pregnant mothers have questioned their nutritional habits: "Will eating more cause my baby to be overweight?" Or, "I'm eating for two, so it won't hurt to have an extra serving, right?"

5 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

TheGhostofOtto1923
4 / 5 (2) May 14, 2018
Oh yeaaa this is like when the hydra hive bug god absorbed Grant Wards memories when it commandeered his dead body after agent Coulson crushed his chest with his artificial hand. On a desert planet elsewhere in the galaxy.

Which comes first - science or fiction?
moranity
3 / 5 (1) May 15, 2018
So if i eat someone's brain i will have their memories?
Or would i need to mince their brain up and inject it into mine?
If we could get RNA from archeological remains, could we experience the lives of the ancients?
We could find out how they made those big round stones in south america, and why; and did they really have polarizable sunglasses and whats with all the human sacrifice.
Whydening Gyre
2 / 5 (1) May 15, 2018
So if i eat someone's brain i will have their memories?
Or would i need to mince their brain up and inject it into mine?
...
and whats with all the human sacrifice.

Did you just answer your own question....?
johnhew
1 / 5 (1) May 16, 2018
planarians
Lorenzo-dArte
not rated yet May 21, 2018
Interesting research and assuming the methods are good it does confirm that protein synthesis is involved in the sensitisation of neurones - but I think we know that already - synaptic receptors are proteins. What does not ring true is the claim that this represents memory and whilst it might be an interesting lead as to how to re-energise neuronal activity, for instance in Parkinson's disease, a cure for dementia still seems as far away as before.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.