Brain HealthProtective brain cells may be quietly driving age-related cognitive decline
Brain aging may involve an unexpected culprit: oligodendrocytes, the cells that build and maintain myelin, the insulating coat around nerve fibers. Researchers from the University of Edinburgh and the UK Dementia Research Institute used data from the Lothian Birth Cohort 1936, which tracked thinking skills from childhood into old age. Donated brain tissue from people who had declined faster showed fewer large nerve fibers and an abnormal buildup of unhealthy myelin, especially around the large fibers that remained. These changes tracked how quickly abilities declined, not how people scored at one point in time. Experiments in mice supported the idea that dysfunctional myelin-producing cells can damage nerve fibers and impair cognition. The pathway involved is already targeted by drugs used for other neurological conditions, so existing medicines might one day be repurposed to protect the aging brain. The work, published in Nature Medicine, challenges the assumption that these cells are always helpful and suggests that more myelin is not always better.
