Key Takeaways
Sleep is important for memory
The neurons that store the day's memories are reset at night, making more space for new memories.
Electrodes implanted in the brains of mice revealed this pattern.
FRIDAY, Aug. 16, 2024 (HealthDay News) — A new study suggests that good sleep is crucial for helping people create new memories.
Neurons that capture new memories during the day are reset during sleep, researchers reported August 15 in the journal Science.
“This mechanism may allow the brain to reuse the same resources, the same neurons, the next day for new learning,” said researcher Azahara Oliva, assistant professor of neurobiology and behavior at Cornell University in Ithaca, New York.
This process revolves around the hippocampus, a brain region crucial to a person's ability to form memories.
When we learn something or have a new experience, neurons in the hippocampus become activated and store those events as memories.
The same neurons then repeat the same pattern of activity during sleep, transferring the day's memories to a larger brain region called the cortex.
But researchers wondered why the hippocampal neurons don't become so full that they prevent new learning.
Electrodes implanted in the hippocampus of mice offered a potential explanation.
The researchers found that neurons that captured the day's memories were reset after sending the most recent memories to the cortex.
According to the researchers, two memory-capturing regions of the hippocampus, CA1 and CA3, appear to be reset during sleep at the urging of a third region called CA2.
“We noticed that there are other hippocampal states where everything goes quiet during sleep,” Oliva said in a university news release. “The CA1 and CA3 regions, which were very active, suddenly become quiet. This is a memory reset, and this state is generated by the intermediate region, CA2.”
The researchers found that the brain contains parallel circuits controlled by two types of neurons: one network of circuits controls memory, and the other allows memories to be reset.
This new understanding could help researchers develop tools to enhance memory by improving the mechanisms of memory consolidation.
The discovery could also lay the foundation for new ways to treat problems caused by unwanted memories, such as post-traumatic stress disorder (PTSD), and cure memory disorders such as Alzheimer's disease.
But overall, the researchers say the findings help explain why sleep is so important for brain health in all animals.
“We've shown that memory is a dynamic process,” Oliva said.
Source: Cornell University, news release, August 15, 2024
What this means for you
Sleep not only helps you rest, it also resets the memory centres of your brain so you can create new memories the next day.
