What does the membrane potential have to do with neurons?

 The membrane potential of neurons is the difference in electrical charge between the inside and the outside of the neuron1.

 In most neurons, the membrane potential is between −60 and −75 millivolts2. 

A resting neuron has a voltage across its membrane called the resting membrane potential, which is determined by concentration gradients of ions across the membrane and by membrane permeability to each type of ion3. 

For neurons, resting potential is defined as ranging from –80 to –70 millivolts4.