A team based at UCLA have recently been able to transfer memories between marine snails by extracting RNA from one and injecting it into the other. This is a first in the field of artificial memory and offers new hope to researchers who are looking for ways to restore memory in patients affected with dementia. It could also prove to be a useful tool to lessen the effects of painful memories in those who have been affected by a trauma.
Memories have long thought to be linked to changes in neuronal synapses, but this study has shown that this may not be the case. Indeed, this study involved transferring RNA between two Aplysia snails and resulted in the transfer of memories, suggesting that RNA may be more involved in memory formation than previously thought.
The experiment, summarised in the figure below, consisted of training a group of snails to respond to receiving mild electric shocks to their tails. When this occurs, snails retract their tails in a defensive mechanism. Untrained snails retracted their tails for only a few seconds, whereas trained animals retracted them for a little under a minute. Animals were considered trained once this difference in time was statistically significant.
Then, RNA was extracted from these animals’ nervous systems and injected into a naïve untrained recipient. These snails were then in turn given a mild electric shock, and it was found that the recipient snails also retracted their tails for a significantly longer amount of time.
As a control, RNA from untrained animals was also injected into untrained recipients, and these showed no significant difference in the length of their defensive contraction.
The results of this experiment suggest that memory can be transferred via RNA and that memory is not related to synapses, as previously thought. David Glanzman, senior author of the paper, said in the UCLA Press release that “if memories were stored at synapses, there is no way [their] experiment would have worked”.
Future work will be needed to determine which type of RNA can be used to transfer memories, but Glanzman hopes that in the future, RNA will be able to be used to restore dormant memories in the early stages of Alzheimer’s Disease, and ameliorate the effects of post-traumatic stress disorder.
This is not the first time that RNA has been suggested as the basis of memory. James McConnell was one of the scientists who, in 1963, suggested a role for RNA in the creation of memories. His theories were however rejected at the time.
McConnell reportedly believed that memory was chemically based and imagined that in the future humanity would be programmable by drugs. Sound familiar? This is the basis of many Sci-Fi plots, where humanity would be able to learn skills and gain knowledge by taking drugs. Sounds useful for exams, but exams probably wouldn’t be necessary if all you needed to do was buy the pills needed to acquire the knowledge and skills for a certain profession.
What do you think about the possibility of memory transfer? Let me know in the comments below!
Original paper: Bédécarrats, A., Chen, S., Pearce, K., Cai, D., Glanzman, D. (2018) “RNA from Trained Aplysia Can Induce an Epigenetic Engram for Long-Term Sensitization in Untrained Aplysia”, eNeuro, 5(3), ENEURO.0038-18.2018 – Read here