an equivalent circuit represents all of the important electrical properties of a neuron using conductors, resistors, batteries, and capacitors.
the lipid bilayer gives the cells capacitance but it is a leaky capacitor because of its ion channels that open and close
ion channels give membrane conductance but each channel must be considered separately.
references
Kandel, E. R., Koester, J., Mack, S., & Siegelbaum, S. (Eds.). (2021). Principles of neural science (Sixth edition). McGraw Hill.