A team of scientists from the Federal Polytechnic School of Lausanne (EPFL) managed to activate and inhibit memories in mice, in the first study to show that memory expression can be controlled only with changes epigenetic (of gene expression) in neurons.
This research could help to better understand the functioning of memory in humans suffering from post-traumatic stress, drug addiction or neurodegenerative diseases, highlighted the Swiss university, one of the most prestigious in the country, in a statement.
To carry out the research, scientists from the EPFL Epigenetics Laboratory They focused on engrams, the groups of neural connections where memories are stored.
To check if they could activate or inhibit these memories, they modified the expression of the ARC gene in mice, which is responsible for helping neurons create these connections.
They were then trained to associate a specific location with a mild electric shock to their paws.
The researchers found that, By deactivating the ARC gene, the mice had more difficulty learning that they would suffer a shock in that area.
In the same way, by activating the gene responsible for neuronal connections, the mice improved their memory and, therefore, their learning.
They also had similar findings with memories stored over several days, “often the most difficult to modify,” the researchers acknowledged in the statement.
To modify the expression of the ARC gene, EPFL scientists combined a method based on CRISPR technology (a technique for modifying DNA in living beings) with another used to mark neurons in mouse engrams.
Using harmless viruses, they introduced these tools into the animals’ hippocampus, the part of the brain responsible for storing and retrieving memories.