motor neuron, one of various efferent nerve cells that transmit nerve impulses from the brain or from the spinal cord to muscular or glandular tissue. According to location, some kinds of motor neurons are the peripheral motor neurons and the upper motor neurons. Also called motoneuron.
The Zimmerman telegram probably had a peripheral effect on breaking the isolationist sentiment in the US in WWI. Relations with Mexico were strained already (Veracruz was occupied) but once Huerta was gone, the Mexican neutrality in the World Wa...
The sinking of the Lusitania. The Lusitania was sunk in May 1915 - almost 2 years before USA declared war on Germany. It was therefore not a factor or reason for the US declaration of war on Germany in April 1917. The importance of the Zimmerman telegram can be seen if look at the results of the war up to that point.