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Memories inform our everyday actions and guide our behaviours. However, when new memories are formed, they’re not made against a blank slate, but against the backdrop of our prior experiences. So, what if consecutive memories exert opposing demands on the brain? For example, can a ‘robust’ memory of a previous salient event prevent an individual from forming a new related memory that would require flexible updating?
Researchers at the Dupret laboratory used 'food-context conditioning' to train mice over several days to acquire a robust contextual memory by offering them a choice of high fat foods or their normal chow pellets in different environments. They then measured the ability of the mice to continually keep track of objects placed in their environment: remembering old objects and exploring new ones.
Results showed the mice with robust memory of a high fat foods failed to distinguish new objects placed in their environment, demonstrating how a robust contextual memory can prevent the formation of new memories. The robust memory recruits a steady amount of nerve cells, a hiring process that later blunts the formation of new flexible memories.