Irina Conboy, from the University of California – Berkeley (US), and colleagues have identified a critical biochemical pathway linked to the aging of human muscle. By manipulating these pathways, the researchers were able to restore the muscle's ability to repair and rebuild itself, offering hope for future injury repair and anti-aging techniques. The team studied samples of muscle tissue from nearly 30 old and young healthy men who participated in an exercise physiology study, identifying that the ability of adult stem cells to repair and replacing damaged human muscle tissue is governed by the molecular signals they get from surrounding muscle tissue, and that those signals change with age in ways that preclude productive tissue repair.   The team concludes that the “aging of human muscle maintenance and repair can be reversed by youthful calibration of specific molecular pathways.” They are hopeful that "This provides promising new targets for forestalling the debilitating muscle atrophy that accompanies aging, and perhaps other tissue degenerative disorders as well."