Newborn mouse pups experience permanent brain changes when repeatedly overstimulated.
Researchers stimulated young mice pups by excessively touching the pups' whiskers, prolonging treadmill sessions or playing chronic noise. When stimulated in one of these ways for five days or longer, the mice's brains had smaller, less-branched blood vessels.
If the overstimulation lasted longer than a month, the effects were permanent. The changes could deliver less oxygen to the brain and alter the way the animals' nerve cells work, the team reports December 4 in Nature.
Similar effects could happen in overstimulated human infants, leaving individuals more prone to hypertension, diabetes and aging. But more research needs to be done to determine if the effects observed in mice occur in humans, the scientists note.