According to a new study from Cornell University, a good night’s sleep restores energy and resets memory. When we learn something new, neurons in the hippocampus activate. During sleep, these neurons replay the same activity, helping to store memories in the brain’s cortex. This process allows us to keep learning new things throughout our lives without running out of neurons.
The study titled “A Hippocampal Circuit Mechanism to Balance Memory Reactivation During Sleep,” published on August 15 in Science, found that certain parts of the hippocampus go silent during deep sleep, allowing neurons to reset. This reset helps the brain use the same neurons for new learning the next day. The study also discovered that the CA2 region of the hippocampus plays a vital role in this process.
The researchers implanted electrodes in the hippocampi of mice to record brain activity during learning and sleep. They noticed that during sleep, neurons in the CA1 and CA3 regions repeated the patterns formed during learning. However, they also discovered that, at times, these regions went silent, which helps reset the brain for new learning. The middle area, CA2, controls this reset.
The study’s findings have practical implications for memory enhancement and neurological disorders. Pyramidal neurons are crucial for learning, while interneurons help manage memory. The researchers discovered that different interneurons control memory storage and resetting. This discovery could potentially lead to methods for boosting memory in conditions like Alzheimer’s and even erasing traumatic memories to treat PTSD.
The study reveals that sleep is crucial for fixing memories and resetting the brain to keep it functioning during the day. Memory is a dynamic process. The research, supported by various grants, helps explain why all animals need sleep.
Journal reference :
- Lindsay A. Karaba, Heath L. Robinson et al., A hippocampal circuit mechanism to balance memory reactivation during sleep. Science. DOI: 10.1126/science.ado5708.