Biologists from the University of California Los Angeles published a study in the journal eNeuro explaining how they "implanted" a memory from one slug into another. Glanzman and his colleagues' work arrives at what might be a pivotal moment in our understanding of memory.
"Engram" is the word used to denote the physical substrate of memory - the structure inside the brain that physically stores long term memories, broadly analogous to the way a hard-drive stores data on a computer. While this component hasn't been yet discovered, the process includes epigenetic modification. So, Glanzman and his team researched if they can transfer long-term memory through the molecule. The injected snails reacted to gentle touches in the same way that the zapped snails had, while those injected with RNA from untrained snails withdrew for only a short time.
In an experiment, researchers inflicted painless electric shocks to sea snails known as Aplysia californica. When they were shocked, the snails that weren't injected with RNA curled for only a few seconds, the way all snails do when they haven't been trained.
A second, untrained, group of snails only retreated for 1 second upon receiving a tap. This meant that the memory of the electric shocks were transmitted from the shocked snails to the unshocked and un-exposed snails.
Once this initial phase of the experiment was completed, the researchers extracted RNA from the sensitized sea hare snails and injected it into untrained specimens.
The trained RNA also increased the excitability of cultured sensory neurons, obtained from untrained animals, which control this reflex all of which raises the possibility that RNA could be used to modify memory in other organisms, including us. As for the snails, the team trained then beforehand to develop a defensive reaction to this procedure.
But Ryan added that radical thinking about memory was sorely needed: "In a field like this which is so full of dogma, where we are waiting for people to retire so we can move on, we need as many new ideas as possible". Then, for good measure, they dribbled that same RNA over a bundle of loose neurons in a petri dish. "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. This new study was funded by the National Institutes of Health and the National Science Foundation.
In addition, the cells and molecular processes of marine snails are similar to those of humans and the result is an important step towards alleviating the effects of diseases such as Alzheimer's or post-traumatic stress disorder. Andre specializes in environmental health, but writes on a variety of issues.