RNA transfer could preserve or destroy memory
Shocking Snails, Making Memories
Researchers from the University of California in Los Angeles (UCLA) showed that they could transfer memories by injecting RNA from one marine snail to another, reported Arlene Weintraub in Fierce Biotech. The researchers hope that the new method could result in new Alzheimer’s treatments.
By mildly shocking the tails of a group of Aplysia snails, the UCLA researchers produced a defensive reflex that the snails demonstrated every time they were tapped. When the researchers extracted RNA from the nervous systems of the snails and transferred it to snails that had not gotten the shocks, the new recipients exhibited the same defensive reaction. The researchers, who published an article about the experiment in the journal eNeuro, the online journal of the Society for Neuroscience, anticipate that RNA may be used to relieve symptoms of Alzheimer’s or post-traumatic stress disorder.
The UCLA biologists have effectively created an artificial memory. The research could be developed into new ways to reduce the trauma of painful memories from post-traumatic stress disorder (PTSD) or to restore lost memories from Alzheimer’s and similar diseases.
"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," explained David Glanzman, senior author of the study, a UCLA professor of integrative biology and physiology and of neurobiology and a member of UCLA's Brain Research Institute.. Ribonucleic acid (RNA) is a “cellular messenger that makes proteins and carries out DNA's instructions to other parts of the cell,” according to the researcher. RNA also has other important functions in addition to protein coding, including regulation of many cellular processes pertaining to development and disease.
Each snail snails received five tail shocks, one every 20 minutes, and then five more 24 hours later. The shocks amplify the snail's defensive withdrawal reflex, which it exhibits for protection from perceived harm. When the researchers tapped the snails again, they discovered that the ones who had been given the shocks displayed a defensive contraction that lasted about 50 seconds, a simple type of learning known as "sensitization." Snails that had not been given the shocks contracted for only about one second.
The researchers extracted RNA from the nervous systems of marine snails that received the tail shocks the day after the second series of shocks, as well as from marine snails that did not receive any shocks. Then they injected RNA from the first (sensitized) group into seven snails that had not received any shocks, and injected the RNA from the second group into a control group of seven other snails that also had not received any shocks.
The scientists discovered that the seven snails that received the RNA from snails that were given the shocks behaved as if they themselves had gotten the shocks: They exhibited a defensive contraction that lasted an average of about 40 seconds.
"It's as though we transferred the memory," said Glanzman. The control group of snails did not display the lengthy contraction.
Neuroscience researchers have believed that memories are stored in synapses. According to Glanzman, who believes that memories are stored in the nucleus of neurons, "If memories were stored at synapses, there is no way our experiment would have worked. “The marine snail is an excellent model for studying the brain and memory.”