Gating Current

Definition

Gating current is the component of the neuronal transmembrane current due to the movement of charges attached to voltage-gated ion channels.

Detailed Description

Physical Basis

The proteins making up ion channels are arranged into subunits, which are further organized into segments. About a third of the amino acid residues in the S4 segments of voltage-gated ion channels are positively charged arginine and lysine. These gating charges are acted on by the electric field across the membrane, with the force changing the stability of ion channel conformations. The movement of the gating charges perpendicular to the membrane during conformation changes is the gating current. This is distinct from the ionic current, the current due to ions flowing through the channel pore.

The theory of ion channels opened and closed via gating charges was postulated by Hodgkin and Huxley (1952), although they used the term “gates” rather than “ion channels.” They predicted that gating current...