Title: Dynamic neural ensembles support memory stability and flexibility across the lifetime
Abstract : Creating stable memories is critical for survival. An animal relies on past learning to navigate its environment, avoid dangerous situations, and find needed resources. Because the environment is dynamic, stable memories must be updated with new information to enable responses to changing threats (a specific danger) and rewards (such as food and water). The brain circuits involved in memory and learning require both stability and flexibility. Using in vivo calcium imaging, optogenetics, chemogenetics and whole-brain activity-mapping , we discovered that traumatic experiences can alter past memories and have long-lasting changes to how future memories are encoded. This has important implications for how the brain stably stores and flexibly updates memories across the lifetime.