As we get older, our bodies’ ability to regenerate decreases. This is not only true for our skin (which is evident in the wrinkles that develop as we age) but also true for other tissues in the body, including the regenerative processes in the brain. For diseases which often span several decades and are affected by regenerative processes, such as MS, this can have massive implications.
In multiple sclerosis, the insulating layers that protect nerve fibres in the brain, known as myelin sheaths, become damaged. The loss of myelin in the brain prevents nerve fibres from sending signals properly and will eventually lead to the loss of the nerve fibre itself. However, early in the disease, a regenerative process, or remyelination, occurs and the myelin sheaths are restored. Unfortunately, as people with MS age, remyelination decreases significantly, resulting in more nerve fibres being permanently lost.
Image: Myelinated nerve fibres. Credit: Wellcome Images images@wellcome.ac.uk.
Reproduced courtesy University of Cambridge Office of Communications