The lecture will start with the explanation of the basics of membrane physiology, including the ionic composition of intracellular and extracellular solutions, the electro-chemical potential and the equilibrium potential. Next, the mechanism of the determination of the resting potential will be explained. The lecturer will then explain the voltage- and time dependent activity of ion channels which was uncovered by voltage-clamp analysis, and show that the generation of action potential can be reconstituted based on the activity of Na⁺ and K⁺ channels.