Researchers investigated the neuronal mechanisms behind cognitive decline in rats. Their research suggested that some aged individuals may be resilient to cognitive decline, despite experiencing age-related effects at the neuronal level.
The researchers concluded that further research into these compensatory mechanisms could help develop treatments for age-related cognitive decline. Research suggests that the hippocampus, an area in the brain responsible for memory, performs two complementary processes: pattern separation and pattern completion.
Pattern completion could be described as the ability to remember visiting a place when you return there a month later, even if some details have changed. On the other hand, pattern separation is remembering which conversations happened during each visit and not confusing them with each other.
As humans and rodents age, their pattern separation abilities declineTrusted Source. Studies have shown that this may be linked to an overactive CA3 network in the dentate gyrus in the hippocampus. Drugs that reduce this hyperactivity have increased memory performance in aged rats.
A direct study of the CA3 network’s effect on memory could help researchers develop treatments to improve age-related memory issues. Most recently, researchers studied how this CA3 network influenced the memory abilities of young and aged rats.
The researchers found that some aged rats could perform similarly to young rats in memory tasks, even though their brains showed deficits in pattern separation.
The study was published inCurrent BiologyTrusted Source.
Studies in rats
For the study, the researchers obtained four young rats (aged between 3 and 6 months) and 14 older rats (aged between 22 and 26 months). To begin, the rats underwent behavioral testing in a water maze.
They then underwent hyperdrive implant surgery so that researchers could monitor the lateral edge of their CA3 brain region.
Thereafter, they were trained for eight days to locate a submerged escape platform in a water maze tank. Every sixth time in the maze was considered a ‘probe trial’, and included no escape platform for the first 30 seconds.
The researchers used the rats’ average search proximity scores during these probe trials to calculate a learning index.
