A motor neuron is a nerve cell forming part of a pathway along which impulses pass from the brain or spinal cord to a muscle or gland. In layman’s terms, a motor neuron is a type of cell in the nervous system that directly or indirectly controls the contraction or relaxation of muscles, which in most cases leads to movement. If a motor neuron is damaged, the signal from the brain cannot be properly transferred to the respective muscles which would cause the contraction of that muscle to perform insufficiently. This would results in muscle weakness and atrophy of the muscle. This is exactly what takes place in SMA, a lower motor neuron disease. Spinal muscle atrophy is a genetic disease that affects the part of the nervous system that controls
