Most important factor determining whether a receptor-operated ion channel is inhibitory or excitatory is whether the permeant ion's reversal potential is positive or negative to the threshold.
<h3>What are ion channels?</h3>
Ion channels are pore-forming membrane proteins that allow ions to pass through the channel pore.
Their functions include establishing a resting membrane potential, shaping action potentials and other electrical signals by gating the flow of ions across the cell membrane, controlling the flow of ions across secretory and epithelial cells, and regulating cell volume.
Ion channels are one of the two classes of ionophore proteins, the other being ion transporters.
