“You’re talking about memories…”

“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.

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“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.

“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.

“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.”

Text: Biologists ‘transfer’ a memory between snails, University of California.

Pic: Paul Rumsey, Snail, 1988-93.

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To Remember, We Must Forget

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“In order to remember, we must forget. Recent research shows that when your brain retrieves newly encoded information, it suppresses older related information so that it does not interfere with the process of recall. Now a team of European researchers has identified a neural pathway that induces forgetting by actively erasing memories. The findings could eventually lead to novel treatments for conditions such as post-traumatic stress disorder (PTSD).

“We’ve known since the early 1950s that a brain structure called the hippocampus is critical for memory formation and retrieval, and subsequent work using modern techniques has revealed a great deal of information about the underlying cellular mechanisms. The hippocampus contains neural circuits that loop through three of its sub-regions – the dentate gyrus and the CA3 and CA1 areas – and it’s widely believed that memories form by the strengthening and weakening of synaptic connections within these circuits.

[…]

“This is the first time that a pathway in the brain has been linked to forgetting, to actively erasing memories,” said Gross, a co-senior author of the study. “One explanation for [our findings] is that there is limited space in the brain, so when you’re learning, you have to weaken some connections to make room for others. To learn new things, you have to forget things you’ve learned before.”

“The finding that memory loss can be induced by Npy1 receptor activation alone could one day help researchers to treat conditions involving intrusive traumatic memories. “A patient suffering from intrusive traumatic memories would take a pill containing a drug that would enter the brain and activate Npy1 receptors and then be exposed to a virtual experience of the trauma,” says Gross, “and we predict that the combination of receptor activation and trauma exposure and recall would promote the selective erasure of the relevant memory.”

Text:  A neural pathway that erases memories, The Guardian.

Pic: Total Recall, 1990.