Hodgkin-Huxley Model circuit representation of the neuronal membrane. The circuit consists of a capacitor cell generating capacitive current and ion flow across the cell membrane, generating the ionic current. Ion channels and ionic currents cause an acquisition of net charge in the extracellular and depletion of charge in the intracellular space. This leads to a potential difference, V, across the neuronal membrane. (Source: Mind the Graph on https://mindthegraph.com/, used under the CC BY-SA license (https://creativecommons.org/licenses/by-sa/4.0/deed.en)/derivative of the original).