Sleep Primes Brain for New Learning by Stabilizing Memories, Japanese Study Shows

Memory is essential for learning and decision-making. Sleep is known to deepen learning, but its role in preparing the mind for new knowledge was unclear. Researchers at the University of Toyama in Japan, led by Professor Kaoru Inokuchi, investigated this. The study, published recently, examined brain activity in mice before and after learning new tasks. The team focused on engram cells, which store specific memories, and 'engram-to-be' cells, which handle future events. They found that during sleep, engram cells reactivate, stabilizing new memories. Simultaneously, 'engram-to-be' cells coordinate, preparing the brain for new learning. Disrupting sleep impairs this preparation, making memory networks rigid. Simulations showed that disabling synaptic plasticity during sleep hindered the brain's ability to prepare for new learning. Without these changes, the same cells replayed old information, preventing new learning paths from forming. Researchers discovered that some 'common engram cells' act as bridges, connecting past knowledge with new information during sleep. This process clears space in the brain, allowing new learning to take place. Professor Inokuchi suggests that manipulating brain activity during sleep could enhance memory and unlock the brain's potential. The findings have implications for educational strategies, interventions, and memory-related conditions like Alzheimer's disease. Future research will explore the roles of different sleep stages, such as NREM and REM sleep, in memory updates. The team emphasizes the importance of sleep for information processing and overall quality of life. The study highlights that sleep both reinforces existing memories and prepares the brain for future learning. This research could lead to new therapies for cognitive impairments.