New Neurons Found to Overwrite Old MemoriesMay 21, 2014
New Neurons Found to Overwrite Old Memories
The inability of adults to recall experiences from early childhood may be linked to the creation of new neurons in the brain.
Throughout a person’s life, neurons are constantly made in the hippocampus, a region of the brain associated with memory. To see whether this process, known as neurogenesis, could drive the loss of childhood memories, researchers ran tests with animals trained to fear a particular environment through electric shock.
Adult mice that were made to run on a wheel, an activity that encourages the birth of new neurons, quickly lost their fear of the troubling environment, while mice that didn’t run seemed to retain their memories. Infant mice treated with drugs to slow neurogenesis were also better at retaining memories of the shocks than those not given drugs.
Observatory: Radio Signals Skew Birds’ Internal NavigationMAY 12, 2014
Times Topic: Observatory
The researchers ran similar tests on guinea pigs and degus, which experience less infant neurogenesis than other animals. When left untreated, these rodents did not forget the shocks as quickly as infant mice did. But when treated with drugs that stimulate neurogenesis, they, too, were more likely to forget.
“When new neurons are born and mature and integrate into these pre-existing neural circuits, they’re going to change the connections that existed before,” said Katherine Akers, now at Wayne State University and lead author of the study. “Changing these connections might degrade the integrity of the pre-existing memories.”
The findings, published in the journal Science, could help lead to treatments for adults with memory or cognition problems, she said.