SMA Motor Neurons (IMAGE) Harvard Medical School Caption In the right-hand picture is an SMA mouse treated with guanabenz, a compound known to reduce cellular stress, shows healthy junctions between muscle cells (red) and motor nerve fibers (green). In contrast, the untreated SMA mouse (left) has lost its nerve fibers, leaving the muscle cells with no way to receive signals from neurons in the spinal cord. Credit Shi-Yan Ng Usage Restrictions Photo may only be used with appropriate credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.