The polarization of membranes is controlled by sodium, potassium, calcium, and chloride ion channels. There are two types of ion channels involved in the neuromuscular junction and end plate potentials: voltage-gated ion channel and ligand-gated ion channel. Voltage gated ion channels are responsive to changes in membrane voltage which cause the voltage gated ion channel to open and allows certain ions to pass through. Ligand gated ion channels are responsive to certain molecules such as neurotransmitters. The binding of a ligand to the receptor on the ion channel protein causes a conformational change which allows the passing of certain ions.
