Motor neurons or motor nerves were neurons in the central nervous system that controlled muscles.
An ethorin pulse could be used in surgery to stabilize a patient's motor neurons. (VOY: "The Swarm")
In 2372, The Doctor stimulated the motor neurons on Danara Pel's body, while simultaneously making a clumsy attempt to romance her holographic counterpart. (VOY: "Lifesigns")
When Neelix was resurrected with Borg nanoprobes in 2374, The Doctor had to stabilize his motor neurons by reducing his acetylcholine levels. (VOY: "Mortal Coil")
In 2375, Nog suffered severe thermal damage to his femoral motor nerves after being shot in the leg by a Jem'Hadar weapon. Dr. Julian Bashir was unsure if the nerves would be able to stimulate artificial muscle tissue and the leg was ultimately lost. (DS9: "The Siege of AR-558")
In 2376, after apparent dark matter lifeforms had entered William Telfer's body and briefly immobilized him, they activated his motor neurons and allowed him to pass through a force field. (VOY: "Good Shepherd")