Brain cells that normally help protect the brain may play an unexpected role in cognitive decline as we grow older. Scientists have discovered that cells responsible for maintaining the protective coating around nerve fibers can become dysfunctional with age, potentially contributing to the gradual loss of memory and thinking abilities.

The research, published in Nature Medicine , challenges the long-held belief that these cells are always beneficial. By examining human brain tissue and conducting experiments in mice, researchers found evidence that problems with these normally supportive cells can damage nerve fibers and interfere with cognitive function.

The discovery also points to a possible new approach for protecting the aging brain.…