Hi There!
A nerve signal or impulse is an electrical message that travels along an axon. There is an difference between the inside of the axon and its surroundings. When the nerve is activated, there is a sudden change in the voltage across the wall of the axon, caused by the movement of ions in and out of the neuron. This triggers a wave of electrical activity that passes from the cell body along the length of the axon to the synapse.
Hope This Has Helped
-Adan M
