selectivity originates from its fast activation and slow inactivation. Activation of KA by synchronized versus semi-synchronized input. The continuous black lines represent synchronous input (100%), the gray lines semi-synchronous input (70%). The dashed lines represent values of KA steady-state activation and inactivation at the membrane potentials dictated in A. A: Membrane potential in the soma. B: Current through KA at input site. Note the difference in current around 4 ms. C: Inactivation of KA at input site. The interval 2–10 ms shows that the effect seen in B originates from the dynamical aspects of KA. D: Activation of KAat input site. Note activation around time of input 2–10 ms.