Voltage-gated channels
Voltage-gated ion channels are activated by changes in the membrane potential near the channel. These changes lead to an alteration of the channel conformation , regulating their opening and closing, to allow the flow of ions inside or outside the cell.
Voltage-gated ion channels are usually ion-specific, being the voltage-gated sodium and the voltage-gated potassium ones the most relevant for their crucial role in signal transduction (action potential) in excitable cells like neurons or muscle tissue.