Bone marrow for damaged brains?

A new study suggests that some bone marrow cells can find their way to the brain and develop into working brain cells. Previously, it was believed that the stem cells in bone marrow only produced replacement blood and bone tissue. The findings, published in the Proceedings of the National Academy of Sciences, could eventually lead to new ways of repairing diseased or damaged brains.

Researchers at the US National Institute of Neurological Diseases and Stroke examined post mortem brain samples from female patients who had received bone marrow transplants from male donors. By looking for the presence of a Y chromosome, which is only found in male cells, they were able to identify clumps of donated cells in the brains of all four women. Although the cells only seemed able to reach certain areas of the brain 'the important message is that there are indeed cells in the blood that can enter the human brain and become neurons there' said team leader Dr Eva Mezey. She added that to harness this natural ability, researchers would first have to boost the number of stem cells entering the brain, and then 'convince them' to turn into the types of brain cell needed by the patient.

Another recent study suggests that bone marrow cells might one day be used to treat brain damage caused by the disease multiple sclerosis (MS). A team from St Vincent's Hospital in Sydney injected bone marrow stem cells into the brains of mice affected by an MS-like disease. They found that the cells homed in on areas of recent damage and started to grow into brain cells that make myelin, the nerve-protecting substance that is gradually lost in MS patients.