TECH

Scientists announce 'memory transplant' between snails

Memory transfer had been appearing for decades in science fiction books and films. Now, it seems to be closer to becoming a scientific fact.A team of scientists successfully managed to do a kind of "memory transplant" - transferring genetic material known as RNA from one marine snail to another.Some of the animals involved were trained to develop a defensive response to electrical shocks in the laboratory.When the RNA of these snails was transferred to others who had not been trained, they reacted in the same way as those who had received moderate shocks.The research, published in the eNeuro journal, helps in understanding the physiological basis of memory.RNA stands for ribonucleic acid; it is a molecule linked to the essential functions of living organisms - including the synthesis of proteins in the body that will define gene expression in a more general way.The scientists administered a series of light electric shocks in the tail of the snails of the marine species Aplysia californica.Animals react to adversity by contracting the body. With the shocks, they had contractions that lasted 50 seconds - a kind of extreme defensive reaction.Then, when they lightly touched the animals that received the shocks, they reacted with the same contraction of 50 seconds, while snails that had not received shocks reacted with a contraction of only one second.The next step was to extract RNA from nerve cells of both types of snails, the conditioned and the unconditioned. The molecules were then injected into two groups of untrained snails.
Scientists noted with surprise that the snails that received the RNA from conditioned animals, when touched, reacted with contractions of about 40 seconds. The snails that received the RNA from unconditioned animals showed no change in their defensive behavior.

Purple ink
Scientists noticed a similar effect on sensory cells being analyzed in Petri dishes.Professor of the University of California at Los Angeles (UCLA), David Glanzman, one of the authors of the study, said the results indicate something like "a memory transfer."He also pointed out that the snails used in the experiment were not injured."These snails (used in the study) were frightened and released paint, but they were not physically affected by the crashes," says Glanzman. "These are sea snails." When they perceive threats, they release a beautiful purple color and hide from predators.Traditionally, long-term memories were thought to be stored in the brain's synapses, the junctions between the neurons. Each neuron has thousands of synapses."If the memories were in the synapses, our experiment would not work at all," says the scientist.For Glanzman, the memories are allocated in the nuclei of the neurons. The study addresses some of the hypotheses raised a few decades ago, according to which RNA would be related to memory.
According to the researchers, the cellular and molecular processes in snails are similar to those of humans, although the nervous system of marine animals has only 20,000 neurons - compared to about 100 billion neurons that man has.
It is believed that the results published in eNeuro may contribute to the search for treatments to mitigate the effects of diseases such as Alzheimer's Disease and Post Traumatic Stress Disorder (PTSD).
Asked whether this process could lead to an eventual transplant of acquired memories in life experiences, Glanzman himself said uncertain but expressed optimism that a greater understanding about the mechanism of memory storage may lead to more opportunities to explore different aspects of memory.

Source:bbc.com