Light microscopy of motor nerve endings also known as motor nerve plates. The endings are nerve synapses or neuromuscular junctions that stimulate muscle contractions. The junctions contain acetylcholinesterase an enzyme that stops muscle stimulation by degrading the neurotransmitter acetylcholine (ACh). The nerve axons are stained black and the striations in the skeletal muscle fibres are prominent. Organophosphorus insecticides and nerve gases may cause irreversible inhibition of AChE with serious disabling affects and possible death. Magnification x520 when printed at 10 cm.