Why is it sometimes so difficult for us to recall moments from the past? The answer lies in the creation of new neurons , according to the latest study by an international team of researchers from Canada and Japan.
Neurogenesis or the creation of new neurons is responsible for us forgetting some old memories, a circumstance that occurs in several species, including humans. The researchers wanted to find out if the creation of new neurons, a process that lasts a lifetime, had an effect on our memory .
To do this, they conducted an experiment with mice, guinea pigs and other small rodents using mild electric shocks to provoke fear of that environment. After this, they let some animals exercise with a wheel (physical exercise naturally increases the levels of neurogenesis). The researchers found that the mice that had exercised had largely forgotten the fear or fear that had been induced, while those that did not exercise, still actively remembered the previous electric shocks.
Scientists believe that by reorganizing brain connections and creating new neurons, they also promote forgetfulness, carrying out a kind of “memory cleaning” that destabilizes old memories to create new ones and thus help memory work in a way more efficient.
“We think that neurogenesis has a double effect on memory. The integration of new neurons in the hippocampus seems to facilitate the encoding of new memories, but at the same time it helps to clean up old ones, ”says study co-author Paul Frankland.
The results of the study have been published in the journal Science .
