A "reset button" for memories has been discovered in the brain

Scientists from the University of California and Columbia University have discovered that the locus coeruleus - a small cluster of neurons in the brain stem known for its role in maintaining attention and alertness levels - may help the brain separate one memory from another. The work is published in the journal Neuron.

Researchers used functional MRI and pupil tracking to study how the brain responds to changes in context when memorizing sequences of images. It turned out that during significant transitions - so-called "event boundaries" - the locus coeruleus sometimes produces a brief burst of activity, which is accompanied by memory segmentation: events on different sides of the boundary are remembered as more separate.

This effect was enhanced when the activation of the locus coeruleus was more pronounced, and was accompanied by changes in the hippocampus - especially in the dentate gyrus, which is responsible for distinguishing similar memories. Pupil measurements confirmed the connection: when the context changed, greater pupil dilation was observed, correlating with locus coeruleus activity.

However, participants with signs of chronically increased activity in this area (hyperactivation associated with sustained noradrenaline release) showed reduced sensitivity to "event boundaries." Scientists suggest that with constant "anxiety," the brain stops responding to important signals, which can impair memory structuring - as, for example, in post-traumatic stress disorder or Alzheimer's disease.

The authors note that the results require verification using methods with higher accuracy. In the future, they plan to investigate how regulating arousal levels - through breathing practices or medications - can help restore normal memory segmentation and improve memory function.