Explain how active transport and membrane permeability contribute to maintaining a resting potential of approximately -70 mV across the axon membrane of a neurone.

A researcher incubated a neurone in a medium containing potassium cyanide, a toxic substance that inhibits mitochondrial cytochrome c oxidase and prevents the synthesis of ATP. Following application of the cyanide, the resting potential of the neurone eventually changed from -70 mV to 0 mV. Explain why.