It's really both, neurons communicate electrochemically. Neurons establish a voltage difference across their membrane, typically positive outside, negative inside, by concentrating ions on one side or the other. In a single neuron, the action potential (signal) results in the electric polarity of the cell membrane switching to negative outside, positive inside, with the change in gradient cascading down the length of the axon as ions are allowed to flow across the membrane by voltage-gated ion channels. After depolarization, ions are actively and selectively pumped to either side of the membrane, repolarizing it.

There's a lot more to it than that but it's 100% charge dependent. The change in charge is mediated by the flow of ions across a membrane instead of the flow of electrons through a conductor, hence why it's slower.