Mouse neuromuscular junctions

Motor nerves (green) found in the spinal cord project out long, thin axons to the periphery, where they contact muscles (black background), forming specialised connections or synapses called neuromuscular junctions (NMJs, red). More specifically, the red staining marks what are known as acetylcholine receptors. These are proteins found in the muscle membrane that bind to signals released by the motor neurons and help to cause voluntary muscle contractions. This image was taken of a mouse lumbrical muscle found in the foot. NMJs can be analysed in mouse models of neuromuscular diseases, such as amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA), in order to determine pathology in the motor nervous system. Image width is approximately 800 micrometres.