Forgetting things is as common an event as remembering them, however very little is known about what happens in our brain when we lose our memory. Now, a study published in the journal Neuron has described the molecular signal processing that takes place in neurons to regulate the acquisition and loss of memories in insects, and that could be extrapolated to functioning in humans.
“Until now it was thought that forgetting occurred passively,” explained Ron Davis, from the Scripps scientific research center (California, USA), author of the study. “However, our results show that it is an active process that is regulated, ” he adds.
According to the study, there are two dopamine receptors on specific neurons located in the so-called ‘mushroom bodies’, very dense bundles of neurons that are related to learning and memory in insects. One of the receptors, dDA1, is responsible for obtaining memories, while the other, called DAMB, causes recently acquired knowledge to be forgotten.
Fruit fly experiments
To reach these conclusions, the researchers carried out several experiments with specimens of the fruit fly ( Drosophila melanogaster ), an animal model in which other studies have been carried out on memory that are applicable to humans. The flies were subjected to situations in which they received ‘rewards’, such as food, or ‘punishments’, such as small electric shocks, associated with different smells. During these olfactory memory acquisition processes, the scientists recorded the changes produced in the brain.
The results showed that the same neurotransmitter, dopamine, can induce learning – by stimulating the dDA1- receptor, or forgetting – if it binds to the DAMB receptor. The researchers believe that the coexistence of both mechanisms during the acquisition of new memories serves to filter those that are truly important and fix them in a process called consolidation, after which the memories are safe from forgetting processes mediated by dopamine.
If its results were applicable to humans, this work would open the door to the development of new drugs to treat some pathologies, such as Savant syndrome, very typical among patients with autism. “These people have an amazing memory in some very specific areas,” Davis explained, “but perhaps what happens is not that they have great memory capacity, but a faulty forgetting mechanism. In addition, drugs could be designed to stimulate memory. by inhibiting the forgetting receptors, “he added.
