The loss of muscle stem cells may be a large contributing factor to muscle decline in old age, a study performed on mice found. Previously, it was thought that the loss of motor neurons was the main contributing factor.

This study, which was conducted by the University of Rochester Medical Center researchers, weakened muscle stem cells in mice while keeping motor neurons intact. Muscle decline was significantly sped up. The research showed no evidence to support motor neuron loss played a significant role in muscle decline.

Adults have a stem cell pool within their muscle tissue that responds to exercise or injury by growing new muscle cells. These stem cells die as one ages. The findings support the line of thought that this natural loss of stem cells contributes to the loss of muscle strength that occurs in old age.

The authors say they hope to use the research to develop a drug or therapy that will decrease the speed of muscle stem cell loss.

This study was published in eLife.