New work shows that neurons and other brain cells use DNA double-strand breaks, often associated with cancer, neurodegeneration and aging, to quickly express genes related to learning and memory.  Double-strand breaks in DNA, usually viewed as a dangerous form of genetic damage, can also play a crucial role in normal cellular processes.

Faced with a threat, the brain has to act fast, its neurons making new connections to learn what might spell the difference between life and death. But in its response, the brain also raises the stakes: As an unsettling recent discovery shows, to express learning and memory genes more quickly, brain cells snap their DNA into pieces at many key points, and then rebuild their fractured genome later.