Scientists Discover New Method of Creating Long-Lasting Memories

A new study revealed that the release of memory-enhancing chemicals during attention-grabbing experiences could help increase the memories of events that occurred before or after the interesting experience.

The study, published in the journal Nature, suggests that some events, which are interesting enough, could trigger a release of dopamine from the brain's locus coeruleus (CL) region. Dopamine could help etch memories into the brain just before or soon after the experience, regardless of whether they were related to the event. These explain why people tend to remember certain events in their lives with particular clarity as well as unrelated details surrounding those events.

"Activation of the locus coeruleus increases our memory of events that happen at the time of activation and may also increase the recall of those memories at a later time," explained Dr. Robert Greene, a Professor of Psychiatry and Neurosciences at UT Southwestern Medical Center's Peter O'Donnell Jr. Brain Institute and co-author of the study, in a press release. "The degree to which these memories are enhanced probably has to do with the degree of activation of the LC."

For the study, the researchers 120 mice to establish a link between LC neurons and neuronal circuits of the hippocampus, which receive the dopamine released in the LC and is responsible for recording memories in the brain.

The researchers discovered that the group of mice given a novelty experience did a better job at remembering where to find foods in an arena. Furthermore, the researchers discovered that injecting the brain of the mice with a genetically encoded light-sensitive activator called channelrhodopsin replaced the novelty experience as a memory enhancer. Additionally the activation caused by the channelrhodopsin could cause a direct, long-lasting synaptic strengthening, a process that can mediate improvement of learning and memory.

With their findings, the researchers showed that drugs targeting neurons in the LC may affect memory and learning as well. The LC is located in the brain stem and has a range of functions that affect a person's emotions, anxiety levels, sleep patterns, memory and other aspects of behavior.