Learning hurts your brain

After publishing an especially challenging quantum mechanics article, it's not uncommon to hear some of our readers complain that their head hurts. Presumably, they mean that the article gave them a (metaphoric) headache. But it's actually possible that challenging your brain does a bit of physical damage to the nerve cells of the brain. Researchers are reporting that, following situations where the brain is active, you might find signs of DNA damage within the cells there. The damage is normally restored quickly, but they hypothesize that the inability to repair it quickly enough may underlie some neurological diseases.

This research clearly started out as an attempt to understand Alzheimer's disease. The authors were working with mice that were genetically modified to mimic some of the mutations associated with early-onset forms of the disease in humans. As part of their testing, the team (based at UCSF) looked for signs of DNA damage in the brains of these animals. They generally found that the indications of damage went up when the brains of mice were active—specifically, after they were given a new environment to explore.

That might seem interesting on its own, but the surprise came when they looked at their control mice, which weren't at elevated risk of brain disorders. These mice also showed signs of DNA damage (although at slightly lower levels than the Alzheimer's-prone mice).