Activities such as playing a new video game or tennis may help you create long-lasting memories, a new study in mice suggests.
Attention-grabbing experiences trigger the release of memory-enhancing chemicals. Those chemicals can etch memories into the brain that occur just before or soon after the experience, regardless of whether they were related to the event, according to researchers at University of Texas Southwestern Medical Centre in the US.
The trick to creating long-lasting memories is to find something interesting enough to activate the release of dopamine from the brain's locus coeruleus (LC) region.
"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," said Professor Robert Greene.
"The degree to which these memories are enhanced probably has to do with the degree of activation of the LC," said Greene.
However, life-changing events are not the only way to trigger the release of dopamine in this part of the brain.
It could be as simple as a student playing a new video game during a quick break while studying for a crucial exam, or a company executive playing tennis right after trying to memorise a big speech, researchers said.
"In general, anything that will grab your attention in a persistent kind of way can lead to activation," Greene said.
The study established that dopamine in LC region of the brain can be naturally activated through behavioural actions and that these actions enhance memory retention.
The study suggests that drugs targeting neurons in the locus coeruleus may affect learning and memory as well.
It tested 120 mice to establish a link between locus coeruleus neurons and neuronal circuits of the hippocampus - the region of the brain responsible for recording memories - that receive dopamine from the LC.
Researchers also put the mice in an arena to search for food hidden in sand that changed location each day.
The study found that mice that were given a "novel experience" - exploring an unfamiliar floor surface 30 minutes after being trained to remember the food location - did better in remembering where to find the food the next day.
Researchers correlated this memory enhancement to a molecular process in the brain by injecting the mice with a genetically encoded light-sensitive activator called channelrhodopsin.
They found that selectively activating the channelrhodopsin-labeled neurons with blue light (a technique called optogenetics) could substitute for the novelty experience as a memory enhancer in mice.
Researchers also found that this activation could cause a direct, long-lasting synaptic strengthening - an enhancement of memory-relevant communication occurring at the junctions between neurons in the hippocampus. This process can mediate improvement of learning and memory.
The study was published in the journal Nature.
