Biologists first “transplanted memories” with RNA
Professor David Glantzman and his sea mollusks conceived a small revolution in understanding the mechanism for storing memories.
Any event in the life of higher animals, including man, leaves its imprint in his memory, more precisely the physical trace in the protoplasm. In particular, the carriers of this information are RNA molecules that perform a variety of functions, including the regulation of many cellular processes.
A team of biologists from the University of California in Los Angeles, led by David Glanzman (David Glanzman) for this reason chose the RNA molecule for their experiments with the transfer of memory between living things. And the object of their study were the individuals of the sea mollusk of the species Aplysia californica. Sometimes they are also called sea hares.
To begin with, scientists needed to form a stable memory in one group of animals. Mollusks eventually received five electric shocks (weak, but unpleasant) with an interval of 20 minutes. The experiment was repeated after five hours. The electric shock increases the defensive reflex of the mollusc. Therefore, after a certain time, a pronounced contraction of the muscles of the body was observed in the animals subjected to the test in response to even a slight tapping.
This type of training scientists call "sensitization". The duration of the new protective reaction averaged 50 seconds. At the same time, in the control group of mollusks, which never encountered an electric current, there was a contraction of the body for only one second.
In the next stage, the researchers extracted from the nervous system the trained and untrained aplicies of RNA and introduced them to two other groups of mollusks, each of which had eight individuals. In aplicies, which received RNA experienced by electrocution of the relatives, a protective reaction lasting 40 seconds was observed. As expected, nothing like this happened in the control group.
Leaving the animals alone, the biologists continued their experiments in Petri dishes. They added the RNA of the two original groups of mollusks to sensory and motor neurons isolated from the bodies of untrained aplines.
It is known that the effect of an electric current makes the sensory neurons (motor "does not matter"). Scientists have shown that the proximity of sensory neurons to RNA "beaten" mollusks led to their increased excitability. But motor neurons in a similar company did not show any changes.
But "transplant of memories" was not the ultimate goal for biologists. In neuroscience, for a long time it was considered that memories are stored in synapses, that is, in the places of contacts of two neurons. Glanzmann and some of his colleagues were of a different opinion: they believed that in fact, memories are stored in the nuclei of nerve cells. In experiments with aplicies, the authors of the study sought evidence of their correctness.
"If the memories were stored in synapses, then our experiment would not have worked, “says Glanzman in a university press release, adding that sea mollusks are an excellent model for studying the brain and memory.
To date, according to the results of the study, the authors published an article in the eNeuro edition and continue their work.
In the future, they want to prove that using RNA can be enough to combat Alzheimer’s disease, and to treat people with traumatized memories.