LM of motor end-plate on muscle fibers; neuromuscular junction. Specialized synapses which terminate on skeletal muscle are called motor end plates. synapses between a motor neuron (tree-like) and skeletal muscle cells (bands in background). The end of the axon (large fiber) of a motor neuron in contact with a muscle cell divides into branches, each one terminating in a motor end plate on a different muscle fiber. A single axon thereby has the ability to activate several hundred muscle fibers. The end of each branch divides to form a cluster of small swellings on the muscle surface (visible). The motor end plate fits into a recess in the muscle fiber and releases neurotransmitter chemicals that activate or inhibit muscle activity. A neuromuscular junction (or myoneural junction) is a chemical synapse formed by the contact between a motor neuron and a muscle fiber. It is at the neuromuscular junction that a motor neuron is able to transmit a signal to the muscle fiber, causing muscle contraction. Magnification 50x at 35mm size.